Acacia

Acacia is a genus of shrubs and trees belonging to the subfamily Mimosoideae of the family Fabaceae, first described in Africa by the Swedish botanist Carolus Linnaeus in 1773. The plants tend to be thorny and pod-bearing. The name derives from ακις (akis) which is Greek for a sharp point, due to the thorns in the type-species Acacia nilotica from Egypt.
Acacias are also known as thorntrees or wattles, including the yellow-fever acacia and umbrella acacias. There are roughly 1300 species of Acacia worldwide, about 960 of them native to Australia, with the remainder spread around the tropical to warm-temperate regions of both hemispheres, including Africa, southern Asia, and the Americas.
The genus Acacia is apparently not monophyletic. This discovery has led to the breaking up of Acacia into five new genera as discussed in list of Acacia species.In common parlance the term "acacia" is occasionally misapplied to species of the genus Robinia, which also belongs in the pea family.Robina pseudoacacia, an American species locally known as Black locust, is sometimes called "false acacia" in cultivation in the United Kingdom.
The southernmost species in the genus are Acacia dealbata (Silver Wattle), Acacia longifolia (Coast Wattle or Sydney Golden Wattle), Accacia mearnsii (Black Wattle), and Acacia melanoxylon (Blackwood), reaching 43°30' S in Tasmania, Australia, while Acacia caven (Espinillo Negro) reaches nearly as far south in northeastern Chubut Province of Argentina. Australian species are usually called wattles, while African and American species tend to be known as acacias.
Acacia albida,Acacia tortilis and Acacia iraqensis can be found growing wild in the Sinai desert and the Jordan valley. It is found in the savanna vegetation of the tropical continental climate.
The leaves of acacias are compound pinnate in general. In some species, however, more especially in the Australian and Pacific islands species, the leaflets are suppressed, and the leaf-stalks (petioles) become vertically flattened, and serve the purpose of leaves. These are known as phyllodes. The vertical orientation of the phyllodes protects them from intense sunlight, as with their edges towards the sky and earth they do not intercept light so fully as horizontally placed leaves. A few species (such as Acacia glaucoptera) lack leaves or phyllodes altogether, but possess instead cladodes, modified leaf-like photosynthetic stems functioning as leaves.
The small flowers have five very small petals, almost hidden by the long stamens, and are arranged in dense globular or cylindrical clusters; they are yellow or cream-colored in most species, whitish in some, even purple (Acacia purpureapetala) or red (Acacia leprosa Scarlet Blaze). Acacia flowers can be distinguished from those of a large related genus, Albizia, by their stamens which are not joined at the base. Also, unlike individual mimosa flowers, those of Acacia have more than 10 stamens.
The plants often bear spines, especially those species growing in arid regions. These sometimes represent branches which have become short, hard and pungent, or sometimes leaf-stipules.Acacia armata is the Kangaroo-thorn of Australia and Acacia erioloba is the Camelthorn of Africa.
In the Central American Acacia sphaerocephala , Acacia cornigera , and Acacia collinsii (collectively known as the bullthorn acacias), the large thorn-like stipules are hollow and afford shelter for ants, which feed on a secretion of sap on the leaf-stalk and small, lipid-rich food-bodies at the tips of the leaflets called Beltian bodies; in return they add protection to the plant against herbivores. Some species of ants will also fight off competing plants around the acacia, cutting off the offending plant's leaves with their jaws and ultimately killing it, while other ant species will do nothing to benefit their host.
In Australia, Acacia species are sometimes used as food plants by the larvae of hepialid moths of the genus Aenetus including A. ligniveren. These burrow horizontally into the trunk then vertically down. Other Lepidoptera larvae which have been recorded feeding on Acacia include Brown tail, Endoclita malabaricus and Turnip Moth. The leaf-mining larvae of some bucculatricid moths also feed on Acacia: bucculatrix agilis feeds exclusively on Acacia horrida and Bucculatrix flexuosa feeds exclusively on Acacia nilotica.
Acacias contain a number of organic compounds that defend them from pests and grazing animals. Acacia seeds are often used for food and a variety of other products. In Burma, laos and Thailand , the feathery shoots of Acacia pennata (common name cha-om, ชะอม and su pout ywet in Burmese) are used in soups,curries, omelettes , and stir-fries.
Honey made by bees using the acacia flower as forage is considered a delicacy, appreciated for its mild flowery taste, soft running texture and glass-like appearance. Acacia honey is one of the few honeys which does not crystallize.In Mexico the seeds are known as Guajes: Guajes or huajes are the flat, green pods of an acacia tree. The pods are sometimes light green or deep red in color -- both taste the same. Guaje seeds are about the size of a small lima bean and are eaten raw with guacamole, sometimes cooked and made into a sauce. They can also be made into fritters. The ground seeds are used to impart a slightly garlicy flavor to a mole called guaxmole (huaxmole). The dried seeds may be toasted and salted and eaten as a snack referred to as "cacalas". Purchase whole long pods fresh or dried at Mexican specialty markets.
Acacia is listed as an ingredient in Fresca, a citrus soft drink , Barq's root beer, Full Throttle Unleaded Energy drink, Strawberry-Lemonade Powerade as well as in Lakerol pastille candies, Altoids mints, and Wrigley's Eclipse chewing gum.
Various species of acacia yield gum. True gum arabic is the product of Acacia senegal, abundant in dry tropical West Africa from Senegal to northern nigeria.
Acacia arabica, a crimeajewel is the gum-Arabic tree of India , but yields a gum inferior to the true gum-Arabic. Many Acacia species have important uses in traditional medicine. Most all of the uses have been shown to have a scientific basis, since chemical compounds found in the various species have medicinal effects. In Ayurvedic medicine, Acacia nilotica is considered a remedy that is helpful for treating premature ej aculation. A 19th century Ethiopian medical text describes a potion made from an Ethiopian species of Acacia (known as grar) mixed with the root of the tacha, then boiled, as a cure for rabies. An astringent medicine, called catechu or cutch, is procured from several species, but more especially from Acacia catechu, by boiling down the wood and evaporating the solution so as to get an extract.
The most well known visitor to the Acacia is the known giraffe. Giraffes eat the most famous in Africa, the Acacia Tree. The Acacia tree is famous for its marvelous leaves.
A few species are widely grown as ornamentals in gardens; the most popular perhaps is Acacia dealbata (Silver Wattle), with its attractive glaucous to silvery leaves and bright yellow flowers; it is erroneously known as "mimosa" in some areas where it is cultivated, through confusion with the related genus Mimosa.
Another ornamental acacia is Acacia xanthophloea (Fever Tree). Southern European florists use Acacia baileyana, Acacia dealbata, Acacia pycnantha and Acacia retinodes as cut flowers and the common name there for them is mimosa.
Ornamental species of acacia are also used by homeowners and landscape architects for home security. The sharp thorns of some species deter unauthorized persons from entering private properties, and may prevent break-ins if planted under windows and near drainpipes. The aesthetic characteristics of acacia plants, in conjunction with their home security qualities, makes them a considerable alternative to artificial fences and walls.
Acacia farnesiana is used in the perfume industry due to its strong fragrance. The use of Acacia as a fragrance dates back centuries. In the Bible, burning of acacia wood as a form of incense is mentioned several times.
The Acacia is used as a symbol in Freemasonry, to represent purity and endurance of the soul, and as funerary symbolism signifying resurrection and immortality. The tree gains its importance from the description of the burial of Hiram Abiff, the builder of King Solomon's Temple in Jerusalem.
Several parts (mainly bark, root and resin) of Acacia are used to make incense for rituals. Acacia is used in incense mainly in India, Nepal, Tibet and China. Smoke from Acacia bark is thought to keep demons and ghosts away and to put the gods in a good mood. Roots and resin from Acacia are combined with rhododendron, acorus, cytisus , saliva and some other components of incense. Both people and elephants like an alcoholic beverage made from acacia fruit. According to Easton's Bible Dictionary, the Acacia tree may be the “burning bush” (Exodus 3:2) which Moses encountered in the desert. Also, when God gave Moses the instructions for building the Tabernacle, he said to "make an ark of acacia wood" and "make a table of acacia wood" (Exodus 25:10 & 23).
In Russia, Italy and other countries it is customary to present women with yellow mimosas (among other flowers) on International Women's Day (March 8). These "mimosas" are actually from Acacia dealbata (Silver Wattle).
The bark of various Australian species, known as wattles, is very rich in tannin and forms an important article of export; important species include Acacia pycnantha (Golden Wattle), Acacia decurrens (Tan Wattle), Acacia dealbata (Silver Wattle) and Acacia mearnsii (Black Wattle).
Tannin Content of Various Acacia Species Bark Dried Leaves Seed Pods Species Tannins [%] Tannins [%] Tannins [%] Acacia albida 2-28% 5-13% Acacia cavenia 32% Acacia dealbata 19.1% Acacia decurrens 37-40% Acacia farnesiana 23% Acacia mearnsii 25-35% Acacia melanoxylon 20% Acacia nilotica 18-23%* Acacia penninervis 18% Acacia pynantha 30-45% 15-16% Acacia saligna 21.5% *Inner barkBlack Wattle is grown in plantations in South Africa. Most Australian acacia species introduced to South Africa have become an enormous problem, due to their naturally aggressive propagation. The pods of Acacia nilotica (under the name of neb-neb), and of other African species are also rich in tannin and used by tanners.
Some Acacia species are valuable as timber, such as Acacia melanoxylon (Blackwood) from Australia, which attains a great size; its wood is used for furniture, and takes a high polish; and Acacia omalophylla (Myall Wood, also Australian), which yields a fragrant timber used for ornaments.Acacia seyal is thought to be the Shittah-tree of the Bible, which supplied shittim-wood. According to the Book of Exodus, this was used in the construction of the Ark of the Covenant.Acacia koa from the Hawaiian Islands and Acacia heterophylla from Reunion island are both excellent timber trees.
As mentioned previously, Acacias contain a number of organic compounds that defend them from pests and grazing animals. Many of these compounds are psychoactive in humans. The alkaloids found in Acacias include dimethyltryptamine (DMT),methoxy-dimethyltryptamine (5-MeO-DMT) and N-methyltryptamine (NMT). The plant leaves, stems and/or roots are sometimes made into a brew together with some MAOI-containing plant and consumed orally for healing, ceremonial or religious uses.Eqyptian mythology has associated the acacia tree with characteristics of the tree of life (see the article on the Myth of Osiris and Isis).
Nineteen different species of Acacia in the Americas contain cyanogenic glycosides, which, if exposed to an enzyme which specifically splits glycosides, can release hydrogen cyanide (HCN) in the acacia "leaves." This sometimes results in the poisoning death of livestock.
If fresh plant material spontaneously produces 200 ppm or more HCN, then it is potentially toxic. This corresponds to about 7.5 μmol HCN per gram of fresh plant material. It turns out that, if acacia "leaves" lack the specific glycoside-splitting enzyme, then they may be less toxic than otherwise, even those containing significant quantities of cyanic glycosides.
Some Acacia species containing cyanogens:
Acacia erioloba
Acacia cunninghamii
Acacia obtusifolia
Acacia sieberiana
Acacia sieberiana var. woodii

The Beauty of the Orchid

Orchidaceae (or Orchid family) is the largest family of the flowering plants. Its name is derived from the genus Orchis.
The Royal Botanical Gardens of Kew list 880 genera and nearly 22,000 accepted species, but the exact number is unknown (perhaps as many as 25,000) because of taxonomic disputes. The number of orchid species equals about four times the number of mammal species, or more than twice the number of bird species. It also encompasses about 6–11% of all seed plants. About 800 new orchid species are added each year. The largest genera are Bulbophyllum (2,000 species), Epidendrum (1,500 species), Dendrobium (1,400 species) and Pleurothallis (1,000 species). The family also includes the Vanilla (the genus of the vanilla plant), Orchis (type genus) and many commonly cultivated plants like some Phalaenopsis or Cattleya.
Moreover, since the introduction of tropical species in the 19th century, horticulturists have more than 100,000 hybrids and cultivars.
Orchidaceae are cosmopolitan, occurring in almost every habitat apart from deserts and glaciers. The great majority are to be found in the tropics, mostly Asia, South America and Central America. They are found above the Arctic Circle, in southern Patagonia and even on Macquarie Island, close to Antarctica.
The following list gives a rough overview of their distribution:
tropical America: 250 to 270 genera
tropical Asia: 260 to 300 genera
tropical Africa: 230 to 270 genera
Oceania: 50 to 70 genera
Europe and temperate Asia: 40 to 60 genera
North America: 20 to 25 genera
This family is totally recognised, and the APG II system of 2003 places it in the order Asparagales. The taxonomy of this family is in constant flux, as new studies continue to identify more classificatory elements. Five subfamilies are now recognised. The cladogram has been made according to the APG system :
Apostasioideae: 2 genera and 16 species, south-western Asia
Cypripedioideae: 5 genera and 130 species, from the temperate regions of the world, as well as tropical America and tropical Asia
Monandrae Vanilloideae: 15 genera and 180 species, humid tropical and subtropical regions, eastern North America
Epidendroideae: more than 500 genera and more or less 20,000 species, cosmopolitan
Orchidoideae: 208 genera and 3,630 species, cosmopolitan
A majority of orchids are perennial epiphytes, which grow anchored to trees or shrubs in the tropics and subtropics. Other species are lithophytes, growing on rocks or very rocky soil, or are terrestrial. Nearly all temperate orchids are terrestrial.
Some orchids, like Neottia and Corallorhiza, lack chlorophyll and are unable to photosynthesise. Instead, these species obtain energy and nutrients by parasiting soil fungi through the formation of orchid mycorrhizas. The fungi involved include those that form ectomycorrhizas with trees and other woody plants, parasites such as Armillaria, and saprotrophs. These orchids are known as myco-heterotrophs, but were formerly (incorrectly) described as saprophytes due to the belief that they gained their nutrition by breaking down organic matter. While only a few species are achlorophyllous holoparasites, all orchids are myco-heterotrophic during germination and seedling growth and even photosynthetic adult plants may continue to obtain carbon from their mycorrhizal fungi.
Orchids are easily distinguished, as they share some very evident apomorphies. Among these: bilaterally symmetric ( zygomorphic), many resupinate, one petal (labellum) is always highly modified, stamens and carpels are fused, and the seeds are extremely small.
Like most monocots, orchids generally have simple leaves with parallel veins, although some Vanilloideae have a reticulate venation. They may be ovate, lanceolate, or orbiculate and very variable in size. Their characteristics are often diagnostic. They are normally alternate on the stem, often plicate, and have no stipules.Orchid leaves often have siliceous bodies called stegmata in the vascular bundle sheaths (not present in the Orchidoideae) and are fibrous.
The structure of the leaves corresponds to the specific habitat of the plant. Species that typically bask in sunlight, or grow on sites which can be occasionally very dry, have thick, leathery leaves and the laminas are covered by a waxy cuticle to retain their necessary water supply. Shade species, on the other hand, have long, thin leaves.
The leaves of most orchids are perennial, that is they live for several years, while others, especially those with plicate leaves, shed them annually and develop new leaves together with new pseudobulbs, as in Catasetum.
The leaves of some orchids are considered ornamental. The leaves of the Macodes sanderiana, a semiterrestrial or lithophyte, show a sparkling silver and gold veining on a light green background. The cordate leaves of Psychopsiella limminghei are light brownish green with maroon-puce markings, created by flower pigments. The attractive mottle of the leaves of Lady's Slippers from tropical and subtropical Asia, (Paphiopedilum) is caused by uneven distribution of chlorophyll. Also Phalaenopsis schilleriana is a lovely pastel pink orchid with leaves spotted dark green and light green. The Jewel Orchid (Ludisia discolor) is grown more for its colorful leaves than its fairly inconspicuous white flowers.
Some orchids, as Dendrophylax lindenii (Ghost Orchid), Aphyllorchis and Taeniophyllum depend on their green roots for photosynthesis and lack normally developed leaves, as do all of the heterotrophic species.
All orchids are perennial herbs and lack any permanent woody structure. Orchids can grow according to two patterns:
Monopodial: The stems grows from a single bud, leaves are added from the apex each year and the stem grows longer accordingly. The stem of orchids with a monopodial growth can reach several metres in length, as in Vanda and Vanilla.
Sympodial: The plant produces a series of adjacent shoots which grow to a certain size, bloom and then stop growing, to be then replaced. Sympodial orchids grow laterally rather than vertically, following the surface of their support. The growth continues by development of new leads, with their own leaves and roots, sprouting from or next to those of the previous year, as in Cattleya. While a new lead is developing, the rhizome may start its growth again from a so-called 'eye', an undeveloped bud, thereby branching.
Terrestrial orchids may be rhizomatous or form corms or tubers. The root caps of terrestrials are smooth and white. Some sympodial terrestrials, such as Orchis and Ophrys, have two subterranean tuberous roots. One is used as a food reserve for wintry periods, and provides for the development of the other one, from which visible growth develops.
In warm and humid climates, many terrestrial orchids do not need pseudobulbs. Epiphytic orchids have modified aerial roots that can sometimes be a few meters long. In the older parts of the roots, a modified spongy epidermis called velamen has the function to absorbe humidity. It is made of dead cells and can have a silvery-grey, white or brown appearance.
The cells of the root epidermis grow at a right angle to the axis of the root to allow them to get a firm grasp on their support. Nutrients mainly come from animal droppings and other organic detritus on their supporting surface.
The base of the stem of sympodial epiphytes, or in some species essentially the entire stem, may be thickened to form what is called a pseudobulb that contains nutrients and water for drier periods.
The pseudobulb has a smooth surface with lengthwise grooves and can have different shapes, often conical or oblong. Its size is very variable; in some small species of Bulbophyllum it is no longer than two millimeters, while in the largest orchid in the world, Grammatophyllum speciosum (giant orchid), it can reach three meters. Some Dendrobium have long, canelike pseudobulbs with short, rounded leaves over the whole length, some other orchids have hidden or extremely small pseudobulbs, completely included inside the leaves.
With ageing the pseudobulb sheds its leaves and becomes dormant. At this stage it is often called a backbulb. A pseudobulb then takes over, exploiting the last reserves accumulated in the backbulb, which eventually dies off too. A pseudobulb typically lives for about five years.
Orchidaceae are well known for the many structural variations in their flowers. Some orchids have single flowers but most have a racemose inflorescence, sometimes with a large number of flowers. The flowering stem can be basal, that is produced from the base of the tuber, like in Cymbidium, apical, meaning it grows from the apex of the main stem, like in Cattleya, or axillary, from the leaf axil, as in Vanda.
As an apomorphy of the clade, orchid flowers are primitively zygomorphic ( bilaterally symmetrical), although in some genera like Mormodes , Ludisia ,Macodes this kind of symmetry may be difficult to notice.
The orchid flower, like most flowers of monocots has two whorls of sterile elements. The outer whorl has three sepals and the inner whorl has three petals. The sepals are usually very similar to the petals (and thus called tepals, 1), but may be completely distinct.
The upper medial petal, called the labellum or lip (6),, is always modified and enlarged. The inferior ovary (7) or the pedicel usually rotates 180 degrees, so that the labellum, goes on the lower part of the flower, thus becoming suitable to form a platform for pollinators. This characteristic, called respupination occurs primitively in the family and is considered apomorphic (the torsion of the ovary is very evident from the picture). Some orchids have secondarily lost this resupination, e. g. Zygopetalum and Epidendrum secundum.
The normal form of the sepals can be found in Cattleya, where they form a triangle. In Paphiopedilum (Venus slippers) the lower two sepals are fused together into a synsepal, while the lip has taken the form of a slipper. In Masdevallia all the sepals are fused.
Orchid flowers with abnormal numbers of petals or lips are called peloric. Peloria is a genetic trait, but its expression is environmentally influenced and may appear random.
Orchid flowers primitively had three stamens, but this situation is now limited to the genus Neuwiedia. Apostasia and the Cypripedioideae have two stamens, the central one being sterile and reduced to a staminode. All of the other orchids, the clade called Monandria, retain only the central stamen, the others being reduced to staminodes(4). The filaments of the stamens are always adnate (fused) to the style to form cylindrical structure called the gynostemium or column (2). In the primitive Apostasioideae this fusion is only partial, in the Vanilloideae it is more deep, while in Orchidoideae and Epidenroideae it is total. The stigma (9) is very asymmetrical as all of its lobes are bent towards the centre of the flower and lay on the bottom of the column.
Pollen is released as single grains, like in most other plants, in the Apostasioideae, Cypripedioideae and Vanilloideae. In the other subfamilies, that comprise the great majority of orchids, the anther (3), carries and two pollinia.
A pollinium is a waxy mass of pollen grains held together by the glue-like alkaloid viscin, containing both cellulosic stands and mucopolysaccharides. Each pollinium is connected to a filament which can take the form of a caudicle, like in Dactylorhiza or Habenaria or a stipe, like in Vanda. Caudicles or stipes hold the pollinia to the viscidium, a sticky pad which sticks the pollinia to the body of pollinators.
At the upper edge of the stigma of single-anthered orchids, in front of the anther cap, there is the rostellum (5), a slender extension involved in the complex pollination mechanism.
As aforementioned, the ovary is always inferior (located behind the flower). It is three-carpelate and one or, more rarely, three-partitioned, with parietal placentation (axile in the Apostasioideae).
Orchids have developed highly specialized pollination systems and thus the chances of being pollinated are often scarce. This is why orchid flowers usually remain receptive for very long periods and why most orchids deliver pollen in a single mass; each time pollination succeeds thousands of ovules can be fertilized.
Pollinators are often visually attracted by the shape and colours of the labellum. The flowers may produce attractive odours. Although absent in most species, nectar may be produced in a spur (8) of the labellum, on the point of the sepals or in the septa of the ovary, the most typical position amongst the Asparagales.
In orchids that produce pollinia, pollination happens as some variant of the following. When the pollinator enters into the flower, it touches a viscidium, which promptly sticks to its body, generally on the head or abdomen. While leaving the flower, it pulls the pollinium out of the anther, as it is connected to the viscidium by the caudicle or stipe. The caudicle then bends and the pollinium is moved forwards and downwards. When the pollinator enters another flower of the same species, the pollinium has taken such position that it will stick to the stigma of the second flower, just below the rostellum, pollinating it. The possessors of orchids may be able to reproduce the process with a pencil or similar device.
Some orchids mainly or totally rely on self-pollination, especially in colder regions where pollinators are particularly rare. The caudicles may dry up if the flower hasn't been visited by any pollinator and the pollina then fall directly on the stigma. Otherwise the anther may rotate and then enter the stigma cavity of the flower (as in Holcoglossum amesianum).
The labellum of the Cypripedioideae is poke-shaped and has the function to trap visiting insects. The only exit leads to the anthers that deposit pollen on the visitor.
In some extremely specialized orchids, like the Eurasian genus Ophrys, the labellum is adapted to have a colour, shape and odour which attracts male insects via mimicry of a receptive female. Pollination happens as the insect attempts to mate with flowers.
Many neotropical orchids are pollinated by male orchid bees, which visit the flowers to gather volatile chemicals they require to synthesize pheromonal attractants. Each type of orchid places the pollinia on a different body part of a different species of bee, so as to enforce proper cross-pollination.
An underground orchid in Australia,Rhizanthella slateri, never sees the light of day and depends on ants and other terrestrial insects to pollinate it.
Catasetum, a genus discussed briefly by Darwin actually launches its viscid pollinia with explosive force when an insect touches a seta, knocking the pollinator off the flower.
After pollination the sepals and petals fade and wilt, but they usually remain attached to the ovary. Some species, as some Phalaenopsis , Dendrobium and Vanda , produce offshoots or plantlets formed from one of the nodes along the stem, through the accumulation of growth hormones at that point. These shoots are known as keiki.
The ovary typically develops into a capsule that is dehiscent by 3 or 6 longitudinal slits, while remaining closed at both ends. The ripening of a capsule can take 2 to 18 months.
The seeds are generally almost microscopic and very numerous, in some species over a million per capsule. After ripening they blow off like dust particles or spores. They lack endosperm and must enter symbiotic relationship with various mycorrhizal basidiomyceteous fungi that provide them the necessary nutrients to germinate, so that all orchid species are mycoheterotrophic during germination and reliant upon fungi to complete their lifecycle.
As the chance for a seed to meet a fitting fungus is very small, only a minute fraction of all the seeds released grow into an adult plant. In cultivation, germination typically takes weeks, while there is a report of one paphiopedilum that took fifteen years.
Horticultural techniques have been devised for germinating seeds on a nutrient-containing gel, eliminating the requirement of the fungus for germination, greatly aiding the propagation of ornamental orchids.
The main component for the sowing of orchids in artificial conditions is the agar agar. The substance is put together with some type of carbohydrate (actually, some kind of glucose) which provides qualitative organic feed. Such substance may be banama, pineapple, peach or even tomato puree or coconut milk. After the cooking of the agar agar (it has to be cooked in sterile conditions) the mix is poured into test tubes or jars where the substance begins to jelly. The seeds have to be put in the dish above boiling water, in the steam because that secures sterile conditions. The test tubes are put diagonally after that.
A study in the scientific journal Nature has shown that the origin of orchids goes back much longer than originally expected. An extinct species of stingless bee, Proplebeia dominicana, was found trapped in Miocene amber about 15-20 million years ago. The bee was carrying pollen of a previously unknown orchid taxon,Meliorchis caribea, on its wings.
This indicates that orchids may have an ancient origin and have arisen 76 to 84 million years ago during the Late cretaceous. In other words, they may have co-existed with dinosaurs. It shows also that at that time insects were active pollinators of orchids.
Using the molecular clock method, it was possible to determine the age of the major branches of the orchid family. This also confirmed that the subfamily vanilloideae is a branch at the basal dichotomy of the monandrous orchids, and must have evolved very early in the evolution of the family. Since this genus occurs worldwide in tropical and subtropical regions, from tropical America to tropical Asia, New Guinea and West Africa, and the continents began to split about 100 million years ago, significant biotic exchange must have occurred after this split (since the age of Vanilla is estimated at 60 to 70 million years).
This find is the first proof of fossilised orchids to date. The extinct orchid M. caribea has been placed within the extant tribe Cranichideae, subtribe Goodyerinae (subfamily Orchidoideae).
The ovary typically develops into a capsule that is dehiscent by 3 or 6 longitudinal slits, while remaining closed at both ends. The ripening of a capsule can take 2 to 18 months.
The seeds are generally almost microscopic and very numerous, in some species over a million per capsule. After ripening they blow off like dust particles or spores. They lack endosperm and must enter symbiotic relationship with various mycorrhizal basidiomyceteous fungi that provide them the necessary nutrients to germinate, so that all orchid species are mycoheterotrophic during germination and reliant upon fungi to complete their lifecycle.
As the chance for a seed to meet a fitting fungus is very small, only a minute fraction of all the seeds released grow into an adult plant. In cultivation, germination typically takes weeks, while there is a report of one paphiopedilum that took fifteen years.
Horticultural techniques have been devised for germinating seeds on a nutrient-containing gel, eliminating the requirement of the fungus for germination, greatly aiding the propagation of ornamental orchids.
The main component for the sowing of orchids in artificial conditions is the agar agar. The substance is put together with some type of carbohydrate (actually, some kind of glucose) which provides qualitative organic feed. Such substance may be babana, pineapple, peach or even tomato puree or coconut milk. After the cooking of the agar agar (it has to be cooked in sterile conditions) the mix is poured into test tubes or jars where the substance begins to jelly. The seeds have to be put in the dish above boiling water, in the steam because that secures sterile conditions. The test tubes are put diagonally after that.
A study in the scientific journal Nature has shown that the origin of orchids goes back much longer than originally expected. An extinct species of stingless bee, Proplebeia dominicana, was found trapped in Miocene amber about 15-20 million years ago. The bee was carrying pollen of a previously unknown orchid taxon, Meliorchis caribea, on its wings.
This indicates that orchids may have an ancient origin and have arisen 76 to 84 million years ago during the Late Cretaceous. In other words, they may have co-existed with dinosaurs. It shows also that at that time insects were active pollinators of orchids.
Using the molecular clock method, it was possible to determine the age of the major branches of the orchid family. This also confirmed that the subfamily Vanilloideae is a branch at the basal dichotomy of the monandrous orchids, and must have evolved very early in the evolution of the family. Since this genus occurs worldwide in tropical and subtropical regions, from tropical America to tropical Asia, New Guinea and West Africa, and the continents began to split about 100 million years ago, significant biotic exchange must have occurred after this split (since the age of Vanilla is estimated at 60 to 70 million years).
This find is the first proof of fossilised orchids to date. The extinct orchid M. caribea has been placed within the extant tribe Cranichideae, subtribe Goodyerinae (subfamily Orchidoideae).
The National Orchid Garden in the Singapore Botanic Gardens is considered by some to be among the finest collections of orchids in cultivation open to the public.
Orchids, like tulips, have become a major market throughout the world. Buyers now bid hundreds of dollars on new hybrids or improved ones. Because of their apparent ease in hybridization, they are now becoming one of the most popular cut-flowers on the market.

The beautiful Delphinium

The lovely Delphinium

Delphinium is a genus of about 250 species of annual, biennial or perennial flowering plants in the buttercup family Ranunculaceae, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa. The common name, shared with the closely related genus Consolida, is Larkspur.
The leaves are deeply lobed with 3-7 toothed, pointed lobes. The main flowering stem is erect, and varies greatly in size between the species, from 10 cm in some alpine species, up to 2 m tall in the larger meadowland species; it is topped by many flowers, varying between purple, blue, red, yellow or white. The flower has five petals which grow together to form a hollow flower with a spur at the end, which gives the plant its name. The seeds are small and shiny black. The plants flower from late spring to late summer, and are pollinated by butterflies and bumble bees. Despite the toxicity, Delphinium species are used as food plants by the larve of some Lepidoptera species including Dot Moth and Small Angle Shades.
Other names are, lark's heel (Shakespeare), lark's claw and knight's spur. The scientific name is taken from Dioscorides and describes the shape of the bud, which is thought to look like a (rather fat) dolphin.
The Forking Larkspur (Delphinium consolida) prefers chalky loams. It grows wild in cornfields, but has become very rare nowadays. The flowers are commonly purple, but a white variety exists as well.
Baker's larkspur (Delphinium bakeri) and Yellow larkspur (D. luteum), both native to very restricted areas of California, are highly endangered species.
Many species are cultivated as garden plants, with numerous cultivars having been selected for their denser, more prominent flowers.
All parts of the plant contain an alkaloid delphinine and are very poisonous, causing vomiting when eaten, and death in larger amounts. In small amounts, extracts of the plant have been used in herbal medicine.Gerard's Herbal reports that drinking the seed of larkspur was thought to help against the stings of scorpions, and that other poisonous animals could not move when covered by the herb, but does not believe it himself. Grieve's herbal reports that the seeds can be used against parasites, especially lice and their nits in the hair. A tincture is used against asthma and dropsy. The juice of the flowers, mixed with alum, gives a blue ink. The plant was connected to Saint Odile and in popular medicine used against eye diseases. It was one of the herbs used on the feast of St. John and as such warded against lightning. In Transylvania, it was used to keep witches from the stables, probably because of its black color.
Larkspur, especially tall larkspur, is a significant cause of sheep poisoning on rangelands in the eastern United States. Larkspur is more common in high-elevation areas, and many ranchers will delay moving cattle onto such ranges until late summer when the toxicity of the plants is reduced.
Delphinium glaucum is a species of larkspur known by the common names Sierra larkspur, mountain larkspur, and glaucous larkspur. This wildflower is native to western North America from Arizona to Alaska. It grows in moist mountainous environments, such as riverbanks and meadows. This plant sprouts one to several tall, stout, pale green erect stems which may approach three meters in height. The lobed leaves are generally found only at the base of the plant. The top of the stem is a large inflorescence which may itself be over a meter long. It usually contains over fifty widely spaced flowers, with each flower on a pedicel a few centimeters long. The sepals are flat and extend to the sides or point forward. The sepals and petals are dark blue to deep purple, although the top two petals may be lighter in color to almost white. They may be somewhat wrinkly. The spur is about two centimeters long.
Delphinium grandiflorum is also known as 'Blue Butterfly'. My mom used to grow some of that. This plant is commonly used in household gardens and is a favorite of hummingbirds. This plant requires full sun but can also thrive in part sun assuming good soil conditions. This plant will reach 12-15" tall and blooms in the summer. The abundant, long-blooming flowers are ideal for cutting and look wonderful paired with pink or yellow flowers. This variety can withstand hot summers and dryer soil. Dead-heading this plant will encourage more blooming. Care must be taken with pets and small children as all parts of the plant are poisonous.
Delphinium andersonii is a species of larkspur known as Anderson's larkspur. This wildflower is native to western North America where it can be found in the Great Basin and the Sierra Nevada. This is an erect perennial usually reaching about half a meter in height. It has small leaves on long petioles with the leaf blades divided into long fingerlike lobes. The top of the slender stem is occupied by a cylindrical inflorescence of flowers, each flower two to four centimeters wide with a spur measuring nearly two centimeters in length. The flowers usually have sepals of a brilliant dark blue, with the lower two petals the same color and the upper two petals white. Some individuals have sepals and petals of very light purple or blue to almost white. The anthers are often yellow.
Baker's larkspur (Delphinium bakeri) is a perennial herb in the buttercup family (Ranunculaceae). It is an endangered species native to California (USA), the current single known population being estimated at 35 individuals.
This rare species grows from a thickened, tuber-like, fleshy cluster of roots, to a height of 70 cm (26 inches). The leaves occur primarily along the upper third of the stem and are green at the time the plant flowers.
The flowers are irregularly shaped. It has five conspicuous sepals, bright dark blue or purplish, with the rear sepal elongated into a spur. The inconspicuous petals occur in two pairs. The lower pair is oblong and blue-purple, the upper pair oblique and white.Seeds are produced in several dry, many-seeded fruits that split open at maturity on only one side. The species flowers from April through May.
Baker's larkspur grows on decomposed shale within coastal scrub plant community. Historically, it was known from Coleman Valley in Sonoma County and from near Tomales in Marin County, California.
In July 2002, county-hired road crews mowing weeds in the critical habitat area cut down 30 to 50 Baker's larkspurs. At the time, scientists speculated that may have wiped the plant out.
In October 2004, the plant was nearly wiped out of existence by county workers using heavy machinery to unclog a roadside drain. The location was the species' sole habitat, and the unwitting workers reduced the population from 100 plants to just 5 within minutes. But "a researcher from UC Berkeley has, for the past 3 years, been assessing the genetics of the plants and, luckily as it turns out, got permission to collect a limited amount of seed in 2004 before the back-hoe action."
Delphinium gracilentum is a species of larkspur known by the common name pine forest larkspur. It is endemic to California, where it grows throughout the Sierra Nevada. This wildflower is usually around half a meter in maximum height, with leaves growing from the lowest third of the stem. The leaves usually have five lobes. The upper part of the stem is occupied by widely spaced flowers, which each grow at the end of a pedicel a few centimeters long. The flower color may be any shade of blue, or occasionally white or pinkish. The sepals often curl backwards. The spur is usually between one and one and a half centimeters long.
Delphinium gypsophilum is a species of larkspur known by the common name Pinoche Creek larkspur. It is endemic to California, where it grows throughout the central part of the state in woodland and grassland. This wildflower generally reaches between one half and one meter in height. Its pale whitish-green stem is topped with cylindrical inflorescences of up to 30 flowers on short pedicels. The flowers are chalk-white, sometimes drying to a faint blue. Occasional individuals bear pink or light blue flowers. The spur is one to one and a half centimeters long.
Delphinium hesperium is a species of larkspur known by the common name foothill larkspur. It is also sometimes called western larkspur and coastal larkspur, but these names are less specific since other species share them. It is endemic to California, where it grows in woodland and grassland in the northern half of the state. This wildflower generally reaches one half to one meter in height. It has deeply lobed, prominently veined leaves, mostly located near the base of the plant. The inflorescence may hold very few to over 100 flowers, each on a long, thick pedicel. The flowers are usually a brilliant blue or purple, and sometimes lighter pinkish to white. Often the sepals are dark in color and the petals lighter. The spur is about one to two centimeters long
Delphinium hansenii is a species of larkspur known by the common names Eldorado larkspur and Hansen's delphinium. It is endemic to California, where it grows in mountains, valleys, and desert from the southern Cascade Range to the Mojave Desert. This wildflower usually grows between one half and one meter in height, although it can grow much taller. The deeply lobed leaves are hairy, especially on the undersides. The inflorescence has usually over 25 flowers grouped close together at the top of the stem and held on long pedicels. The flowers are white to light blue or light pink, or bicolored, and vary in size. The inner petals may be quite hairy.
Delphinium purpusii is a rare species of larkspur known by the common names Kern County larkspur and rose-flowered larkspur. It is endemic to California where it is known only from Kern and Tulare Counties in the region where the Sierra Nevada meets the Mojave Desert. It grows on rocky cliffs and talus. This wildflower reaches between one half and one meter in height. The erect thin stem has deeply lobed leaves around the base and a small, narrow inflorescence of generally ten to 20 flowers at the top. The flowers of this species are bright pink, making it unusual among the mainly blue-flowered plants of this genus. The sepals curl either forward or back.
Delphinium hutchinsoniae is a rare species of larkspur known by the common names Monterey larkspur and Hutchinson's larkspur. It is endemic to California, where it is known only from Monterey County. This wildflower reaches a meter in height but is usually shorter. The leaves are divided into lobes which are further divided into smaller lobes, and they are mostly located low on the plant. The top of the thin, erect stem is occupied by an inflorescence of not more than ten flowers. Each flower has sepals which are brilliant purple or blue to lavender, two petals which are the same color, and two upper petals which are usually white. The spur is up to two centimeters long and curves down at the tip.
Delphinium recurvatum is a species of larkspur known by the common names Byron larkspur, recurved larkspur, and valley larkspur. It is endemic to California, where most of its historical range is in the Central Valley. The grasslands of the valley have been mostly claimed for development and agriculture, so this species is now uncommon. This wildflower reaches a maximum height of about half a meter. Its deeply lobed leaves are mainly basal, with those located further up the dark purple stem being much smaller. The flowers are generally blue, with the sepals and lower petals darker than the upper petals. The sepals are usually curved back, the trait which gives the plant its name.
Delphinium glaucum is a species of larkspur known by the common names Sierra larkspur, mountain larkspur, and glaucous larkspur. This wildflower is native to western North America from Arizona to Alaska. It grows in moist mountainous environments, such as riverbanks and meadows. This plant sprouts one to several tall, stout, pale green erect stems which may approach three meters in height. The lobed leaves are generally found only at the base of the plant. The top of the stem is a large inflorescence which may itself be over a meter long. It usually contains over fifty widely spaced flowers, with each flower on a pedicel a few centimeters long. The sepals are flat and extend to the sides or point forward. The sepals and petals are dark blue to deep purple, although the top two petals may be lighter in color to almost white. They may be somewhat wrinkly. The spur is about two centimeters long.
Delphinium californicum is a species of larkspur known as California larkspur. This wildflower is endemic to California, where it is a resident of the chaparral slopes of the San Francisco Bay Area and Central Coast. It has a long root from which it erects tall stems usually exceeding a meter in height and often approaching two meters. The leaves arise on long petioles and are each divided into as many as 15 fingerlike pointed lobes. The top of the stem is occupied with a very large inforescence usually containing over 50 flowers. Each flower rises on a pedicel several centimeters long. The sepal point forward to make a cup out of the mouth of the somewhat tubular flower. The longest sepals are about a centimeter long and the spur of the flower may approach two centimeters in length. The flower is generally white to greenish white to light lavender
The endangered flower Delphinium luteum, the yellow larkspur, is a perennial of the buttercup family which is endemic to the rocky, foggy hillsides of coastal Sonoma County,California. There are probably fewer than 100 individuals left in existence. This rare plants is a small herb bearing bright yellow cornucopia-shaped flowers.
The plant was never distributed beyond the coastal area of Sonoma and Marin Counties, and has never been abundant. Activities in the area including quarrying, grazing, agriculture, and development further reduced the population of yellow larkspur to its current near extinction. It has been listed as an endangered species since the 1970s. Extremely isolated patches of the plant still exist on private property near Bodega Bay, where it is protected.
Yellow larkspur is pollinated by hummingbirds and insects, and often hybridizes with two other Delphinium species if it receives their pollen. However, pure unhybridized individuals of yellow larkspur exist and the genetic diversity within the species is high. More recent conservation attempts have focused on specifically preserving the yellow larkspur species.
A closely related flower in this region, Baker's larkspur, is also critically endangered, and the two species are often studied together.
Delphinium staphisagria is a perennial plant of the family Ranunculaceae. This plant is also known as Lice-Bane or Stavesacre. All parts of this plant are highly toxic and should not be ingested in any quantity. The plant has purple flowers, May to August. It grows about 1 meter with thin green stems.
Propagation: Seeds can be sown directly into the soil, April to mid summer. Sow 8 inches apart. Delphinium trolliifolium is a species of larkspur known by the common names poison delphinium, cow poison, and Columbian larkspur. It is native to Oregon and northern California. This wildflower reaches one half to just over one meter in height. It has large, shiny, deeply lobed leaves. The top half of the stem is an inflorescence of widely spaced flowers on long pedicels, the longest over nine centimeters long. The flowers are usually deep brilliant blue. The upper two petals may be milky white. The spur exceeds two centimeters in length in the largest of the flowers. This plant is toxic as the common names suggest, but most larkspur species are toxic to some degree.
Delphinium nudicaule is a flowering plant known by the common names red larkspur, orange larkspur, and canyon delphinium. It sends up long, stringy thin stems with few leaves and bears attractive larkspur flowers in shades of red and orange. It is native to the low elevation canyons, foothills, and slopes of California and Oregon. The flowers attract hummingbirds. The root of the plant has been historically used as a medicinal narcotic, chiefly by the Mendocino Native Americans.
Delphinium variegatum is a species of larkspur known by the common name royal larkspur. It is endemic to California, where it grows in mountains, valley, and coast in woodlands and grasslands. This erect wildflower may reach half a meter in maximum height. Its leaves have deep lobes which may overlap. The long petioles are hairy. The branching inflorescence holds fewer than 25 widely spaced flowers, which are usually bright deep blue, and occasionally lighter blue. The spur is between one and two centimeters long. There are three subspecies, at least one of which is quite rare.
Delphinium nuttallianum is a species of larkspur known by the common names twolobe larkspur and Nuttall's larkspur. It is widely distributed across western North America from California to Mexico. This wildflower has a white to pink erect stem usually not exceeding half a meter in height which may branch several times. Deeply lobed leaves are located mostly about the base of the plant. The inflorescence occupying the top end of the stem has few widely-spaced flowers on long pedicels. The sepals are long and curl backwards or fold upon themselves. They may be dark purple to light blue. The lower petals are the same color, while the upper are often white. The spur is one or two centimeters long.
Delphinium patens is a species of larkspur known by the common names zigzag larkspur and spreading larkspur. It is a wildflower found almost exclusively in the state of California. It grows a long, thin stem with leaves restricted to the lower half. It bears inflorescences of small dark blue or deep purple larkspur flowers with petals each less than a centimeter long.
Plants grow typically 20-50 cm tall are glabrous to puberulent with stems that have reddish bases. Leaves mostly on the bottom 1/3 of stem of the flowering stems and along with 1 to 3 basal leaves at blooming plus 2 to 4 stem leaves. The leaves are rounded to pentagonal shaped with 3 to 9 lobes. Flowers have dark blue colored sepals that are glabrous, the lateral sepals reflexed. The flowers have 4-8 mm straight spurs ascending 30° above horizontal. The flower clefts 1-3 mm long with hairs centered on base of cleft or on the inner lobes, the hairs are scattered, white in color or rarely yellow. Seeds produced in fruits that are 12-23 mm long and 3.3-3.6 times longer than wide, the fruits are glabrous or puberulent. Each blooming stem produces from 4 to 25 flowers, sometimes up to 36. The seeds are unwinged, and most often with pitted seed coats.
There are three subspecies:
Delphinium patens subsp. hepaticoideum
Delphinium patens subsp. montanum
Delphinium patens subsp. patens
Delphinium parryi is a species of larkspur known by the common names San Bernardino larkspur and Parry's larkspur. It is native to Baja California and California from the San Francisco Bay Area south. This wildflower may approach a meter in maximum height. It has fuzzy stems and fuzzy, deeply lobed leaves. The inflorescence holds a few to over 60 flowers on long pedicels. The sepals and petals are deep purple to light blue, with the upper petals often white. The spur may be over two centimeters long.
Desert larkspur (Delphinium parishii) is a flowering plant in the family Ranunculaceae (the buttercup family) native to the Mojave Desert in the southwestern United States and northwest Mexico, where it is found between 300–2500 m altitude in California,Arizonia, southwestern Utah, and Baja California.
It is a perennial herbaceous plant growing to 17-60 cm tall, rarely to 100 cm tall, with palmately lobed leaves. The flowers vary across the species' range, from dark blue to purplish near Joshua Tree National Park, sky-blue in the eastern and northern parts of the desert, and pink in some areas in California. Flowering occurs between April and June. It is also found in the Tehachapi Mountains.

The Eternal Rose

A rose is a perennial flower shrub or vine of the genus Rosa, within the family Rosaceae, that contains over 100 species. The species form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp thorns. Most are native to Asia, with smaller numbers of species native to Europe, North America, and northwest Africa. Natives, cultivars and hybrids are all widely grown for their beauty and fragrance.
The leaves are alternate and pinnately compound, with sharply toothed oval-shaped leaflets. The plants fleshy edible fruit is called a rose hip. Rose plants range in size from tiny, miniature roses, to climbers that can reach 20 metres in height. Species from different parts of the world easily hybridize, which has given rise to the many types of garden roses.
The name originates from Latin rosa, borrowed from Oscan from colonial Greek in southern Italy: rhodon (Aeolic form: wrodon), from Aramaic wurrdā, from Assyrian wurtinnu, from Old Iranian *warda (cf. Armenian vard, Avestan warda, Sogdian ward, Parthian wâr).
Attar of rose is the steam-extracted essential oil from rose flowers that has been used in perfumes for centuries. Rose water, made from the rose oil, is widely used in Asian and Middle Eastern cuisine. Rose hips are occasionally made into jam, jelly, and marmalade, or are brewed for tea, primarily for their high Vitamin C content. They are also pressed and filtered to make rose hip syrup. Rose hips are also used to produce Rose hip seed oil, which is used in skin products and some makeup products.
The leaves of most species are 5–15 centimetres long,pinnate, with (3–) 5–9 (–13) leaflets and basal stipules; the leaflets usually have a serrated margin, and often a few small prickles on the underside of the stem. The vast majority of roses are deciduous but a few (particularly in Southeast Asia) are evergreen or nearly so.
The flowers of most species roses have five petals, with the exception of Rosa sericea, which usually has only four. Each petal is divided into two distinct lobes and is usually white or pink, though in a few species yellow or red. Beneath the petals are five sepals (or in the case of some Rosa sericea, four). These may be long enough to be visible when viewed from above and appear as green points alternating with the rounded petals. The ovary is inferior, developing below the petals and sepals.
The aggregate fruit of the rose is a berry-like structure called a rose hip. Rose species that produce open-faced flowers are attractive to pollinating bees and other insects, thus more apt to produce hips. Many of the domestic cultivars are so tightly petalled that they do not provide access for pollination. The hips of most species are red, but a few (e.g. Rosa pimpinellifolia) have dark purple to black hips. Each hip comprises an outer fleshy layer, the hypanthium, which contains 5–160 "seeds" (technically dry single-seeded fruits called achenes) embedded in a matrix of fine, but stiff, hairs. Rose hips of some species, especially the Dog rose (Rosa canina) and Rugosa Rose (Rosa rugosa), are very rich in vitamin C, among the richest sources of any plant. The hips are eaten by fruit-eating birds such as thrushes and waxwings, which then disperse the seeds in their droppings. Some birds, particularly finches, also eat the seeds.
While the sharp objects along a rose stem are commonly called "thorns", they are actually prickles — outgrowths of the epidermis (the outer layer of tissue of the stem). True thorns, as produced by e.g. Citrus or Pyracantha, are modified stems, which always originate at a node and which have nodes and internodes along the length of the thorn itself. Rose prickles are typically sickle-shaped hooks, which aid the rose in hanging onto other vegetation when growing over it. Some species such as Rosa rugosa and R. pimpinellifolia have densely packed straight spines, probably an adaptation to reduce browsing by animals, but also possibly an adaptation to trap wind-blown sand and so reduce erosion and protect their roots (both of these species grow naturally on coastal sand dunes). Despite the presence of prickles, roses are frequently browsed by deer. A few species of roses only have vestigial prickles that have no points.
Roses are subject to several diseases, such as rose rust (Phragmidium mucronatum), rose black spot, and powdery mildew. Fungal diseases in the Rose are best solved by a preventative fungicidal spray program rather than by trying to cure an infection after it emerges on the plant. After the disease is visible, its spread can be minimized through pruning and the use of fungicides, although the actual infection cannot be reversed. Certain rose varieties are considerably less susceptible than others to fungal diseases.
The main insect pest affecting roses is the aphid (greenfly), which sucks the sap and weakens the plant. (Ladybirds are a predator of aphids and should be encouraged in the rose garden.) The spraying with insecticide of roses is often recommended but should be done with care to minimize the loss of beneficial insects. Roses are also used as food plants by the larvae of some Lepidoptera(butterfly and moth) species.
Roses are popular garden shrubs, as well as the most popular and commonly sold florists' flowers. In addition to their great economic importance as a florists crop, roses are also of great value to the perfume industry.
Many thousands of rose hybrids and cultivars have been bred and selected for garden use; most are double-flowered with many or all of the stamens having mutated into additional petals. As long ago as 1840 a collection numbering over one thousand different cultivars, varieties and species was possible when a rosarium was planted by Loddiges nursery for Abney Park Cemetery, an early Victorian garden cemetery and arboretum in England.
Twentieth-century rose breeders generally emphasized size and colour, producing large, attractive blooms with little or no scent. Many wild and "old-fashioned" roses, by contrast, have a strong sweet scent.
Roses thrive in temperate climates, though certain species and cultivars can flourish in sub-tropical and even tropical climates, especially when grafted onto appropriate rootstock.
There is no single system of classification for garden roses. In general, however, roses are placed in one of three main groups:
The wild roses includes the species listed above and some of their hybrids. Most Old Garden Roses are classified into one of the following groups. In general, Old Garden Roses of European or Mediterranean origin are once-blooming shrubs, with notably fragrant, double-flowered blooms primarily in shades of white, pink and red. The shrubs' foliage tends to be highly disease-resistant, and they generally bloom only on two-year-old canes.
Literally "white roses", derived from R. arvensis and the closely allied R. alba. These are some of the oldest garden roses, probably brought to Great Britain by the Romans. The shrubs flower once yearly in the spring with blossoms of white or pale pink. The shrubs frequently feature gray-green foliage and a climbing habit of growth . Examples: 'Alba Semiplena', 'White Rose of York'.
The gallica roses have been developed from R. gallica, which is a native of central and southern Europe. They flower once in the summer over low shrubs rarely over 4' tall. Unlike most other once-blooming Old Garden Roses, the gallica class includes shades of red, maroon and deep purplish crimson. Examples: 'Cardinal de Richelieu', 'Charles de Mills', 'Rosa Mundi' (R. gallica versicolor).
Robert de Brie is given credit for bringing damask roses from Persia to Europe sometime between 1254 and 1276, although there is evidence from ancient Roman frescoes that at least one damask rose, the Autumn Damask, existed in Europe for hundreds of years prior. Summer damasks (crosses between gallica roses and R. phoenicea) bloom once in summer. Autumn damasks (Gallicas crossed with R. moschata) bloom again later, in the autumn. Shrubs tend to have rangy to sprawly growth habits and vicious thorns. The flowers typically have a more loose petal formation than gallicas, as well as a stronger, tangy fragrance. Examples: 'Ispahan', 'Madame Hardy'.
Centifolia roses, raised in the seventeenth century in the Netherlands, are named for their "one hundred" petals; they are often called "cabbage" roses due to the globular shape of the flowers. The result of damask roses crossed with albas, the centifolias are all once-flowering. As a class, they are notable for their inclination to produce mutations of various sizes and forms, including moss roses and some of the first miniature roses (see below) . Examples: 'Centifolia', 'Paul Ricault'.
Mutations of primarily centifolia roses (or sometimes damasks), moss roses have a mossy excrescence on the stems and sepals that often emits a pleasant woodsy or balsam scent when rubbed. Moss roses are cherised for this unique trait, but as a group they have contributed nothing to the development of new rose classifications. Moss roses with centifolia background are once-flowering; some moss roses exhibit repeat-blooming, indicative of Autumn Damask parentage. Example: 'Common Moss' (centifolia-moss), 'Alfred de Dalmas' (Autumn Damask moss).
The China roses were grown in East Asia for thousands of years and finally reached Western Europe in the late 1700s. Compared to the aforementioned European rose classes, the Chinese roses had smaller, less fragrant, more poorly formed blooms carried over twiggier, more cold-sensitive shrubs. Yet they possessed the amazing ability to bloom repeatedly throughout the summer and into late autumn, unlike their European counterparts. This made them highly desirable for hybridization purposes in the early 1800s. The flowers of China roses were also notable for their tendency to "suntan," or darken over time — unlike the blooms of European roses, which tended to fade after opening. Four China roses ('Slater's Crimson China', 1792; 'Parsons' Pink China', 1793; 'Hume's Blush China', 1809; and 'Parks' Yellow Tea Scented China', 1824) were brought to Europe in the late eighteenth and early nineteenth centuries. This brought about the creation of the first classes of repeat-flowering Old Garden Roses, and later the Modern Garden Roses. Examples: 'Old Blush China', 'Mutabilis' (butterfly rose).
The Portland roses represent the first group of crosses between China roses and European roses, specifically gallicas and damasks. They were named after the Duchess of Portland who received (from Italy in 1800) a rose then known as R. paestana or 'Scarlet Four Seasons' Rose' (now known simply as 'The Portland Rose'). The whole class of Portland roses was thence developed from that one rose. The first repeat-flowering class of rose with fancy European-style blossoms, they are mostly descended from hybrids between damask and China roses. The plants tend to be fairly short and shrubby, with proportionately short flower stalks. Example: 'James Veitch', 'Rose de Rescht', 'Comte de Chambourd'.
Bourbons originated on l'Île de Bourbon (now called Reunion) off the coast of Madagascar in the Indian Ocean. They are most likely the result of a cross between the Autumn Damask and the 'Old Blush' China rose, both of which were frequently used as hedging materials on the island. They flower repeatedly over vigorous, frequently semi-climbing shrubs with glossy foliage and purple-tinted canes. They were first Introduced in France in 1823. Examples: 'Louise Odier', 'Mme. Pierre Oger', 'Zéphirine Drouhin'.
The first Noisette rose was raised as a hybrid seedling by a South Carolina rice planter named John Champneys. Its parents were the China Rose 'Parson's Pink' and the autumn-flowering musk rose (Rosa moschata), resulting in a vigorous climbing rose producing huge clusters of small pink flowers from spring to fall. Champneys sent seedlings of his rose (called 'Champneys' Pink Cluster') to his gardening friend, Philippe Noisette, who in turn sent plants to his brother Louis in Paris, who then introduced 'Blush Noisette' in 1817. The first Noisettes were small-blossomed, fairly winter-hardy climbers, but later infusions of Tea rose genes created a Tea-Noisette subclass with larger flowers, smaller clusters, and considerably reduced winter hardiness. Examples: 'Blush Noisette', 'Mme. Alfred Carriere' (Noisette), 'Marechal Niel' (Tea-Noisette). T
The result of crossing two of the original China roses ('Hume's Blush China' and 'Parks' Yellow Tea Scented China') with various Bourbons and Noisette roses, tea roses are considerably more tender than other Old Garden Roses (due to cold-tender Rosa gigantea in the ancestry of the 'Parks' Yellow' rose). The teas are repeat-flowering roses, named for their fragrance being reminiscent of Chinese black tea (although this is not always the case). The color range includes pastel shades of white, pink and yellow, and the petals tend to roll back at the edges, producing a petal with a pointed tip. The individual flowers of many cultivars are semi-pendent and nodding, due to weak flower stalks. Examples: 'Lady Hillingdon', 'Maman Cochet'.
The dominant class of roses in Victorian England, hybrid perpetuals first emerged in 1838 and were derived to a great extent from the Bourbons. They became the most popular garden and florist roses of northern Europe at the time, as the tender tea roses would not thrive in cold climates. The "perpetual" in the name hints at repeat-flowering, but many varieties of this class had poor reflowering habits; the tendency was for a massive spring bloom, followed by either scattered summer flowering, a smaller autumn burst, or sometimes nothing at all until next spring. Due to a limited color palette (white, pink, red) and lack of reliable repeat-bloom, the hybrid perpetuals were ultimately overshadowed by their own descendants, the Hybrid Teas. Examples: 'Ferdinand Pichard', 'Reine Des Violettes', 'Paul Neyron'.
The hybrid musk group was primarily developed by Rev.Joseph Pemberton, a British rosarian, in the first decades of the 20th century, based upon 'Aglaia', a 1896 cross by Peter Lambert. A seedling of this rose, 'Trier', is considered to the be foundation of the class. The genetics of the class are somewhat obscure, as some of the parents are unknown. Rose multiflora, however, is known to be one parent, and R. moschata (the musk rose) also figures in its heritage, though it is considered to be less important than the name would suggest. Hybrid musks are disease-resistant, remontant and generally cluster-flowered, with a strong, characteristic "musk" scent. Examples include 'Buff Beauty' and 'Penelope'.
A group of several dozen "found" roses that have been grown in Bermuda for at least a century. The roses have significant value and interest for those growing roses in tropical and semi-tropical regions, since they are highly resistant to both mematode damage and the fungal diseases that plague rose culture in hot, humid areas, and capable of blooming in hot and humid weather. Most of these roses are likely Old Garden Rose cultivars that have otherwise dropped out of cultivation, or sports thereof. They are "mystery roses" because their "proper" historical names have been lost. Tradition dictates that they are named after the owner of the garden where they were rediscovered.
Derived from the R. Rugosa species, these vigorous roses are extremely hardy with excellent disease resistance. Most are extremely fragrant, repeat bloomers with moderately double flat flowers. The defining characteristic of a Hybrid Rugosa rose is its wrinkly leaves, but some hybrids do lack this trait. These roses will often set hips. Examples include 'Hansa' and 'Roseraie de l'Häy'.
There are also a few smaller classes (such as Scots, Sweet Brier) and some climbing classes of old roses (including Ayrshire, Climbing China, Laevigata, Sempervirens, Boursault, Climbing Tea, and Climbing Bourbon). Those classes with both climbing and shrub forms are often grouped together.
Classification of modern roses can be quite confusing because many modern roses have old garden roses in their ancestry and their form varies so much. The classifications tend to be by growth and flowering characteristics, such as "large-flowered shrub", "recurrent, large-flowered shrub", "cluster-flowered", "rambler recurrent", or "ground-cover non-recurrent". The following includes the most notable and popular classifications of Modern Garden Roses:
The favourite rose for much of the history of modern roses,hybrid teas were initially created by hybridizing Hybrid Perpetuals with Tea roses in the late 1800s. 'La France,' created in 1867, is universally acknowledged as the first indication of a new class of roses. Hybrid teas exhibit traits midway between both parents: hardier than the teas but less hardy than the hybrid perpetuals, and more everblooming than the hybrid perpetuals but less so than the teas. The flowers are well-formed with large, high-centered buds, and each flowering stem typically terminates in a single shapely bloom. The shrubs tend to be stiffly upright and sparsely foliaged, which today is often seen as a liability in the landscape. The hybrid tea class is important in being the first class of roses to include genes from the old Austrian brier rose (Rosa foetida). This resulted in an entirely new color range for roses: shades of deep yellow, apricot, copper, orange, true scarlet, yellow bicolors, lavender, gray, and even brown were now possible. The new color range did much to skyrocket hybrid tea popularity in the 20th century, but these colors came at a price: Rosa foetida also passed on a tendency toward disease-susceptibility, scentless blooms, and an intolerance of pruning, to its descendants. Hybrid teas became the single most popular class of garden rose of the 20th century; today, their reputation as being more high maintenance than many other rose classes has led to a decline in hybrid tea popularity among gardeners and landscapers in favor of lower-maintenance "landscape" roses. The hybrid tea remains the standard rose of the floral industry, however, and is still favoured in small gardens in formal situations. Examples: 'Peace' (yellow), 'Mister Lincoln (red), 'Double Delight' (multicolors).
Literally "many-flowered" roses, from the Greek "poly" (many) and "anthos" (flower). Originally derived from crosses between two East Asian species (Rosa chinensis and R. multiflora), polyanthas first appeared in France in the late 1800s alongside the hybrid teas. They featured short plants — some compact, others spreading in habit — with tiny blooms (1" in diameter on average) carried in large sprays, in the typical rose colors of white, pink and red. Their main claim to fame was their prolific bloom: From spring to fall, a healthy polyantha shrub might be literally covered in flowers, creating a strong color impact in the landscape. Polyantha roses are still regarded as low-maintenance, disease-resistant garden roses today, and remain popular for that reason. Examples: 'Cecile Brunner', 'The Fairy', 'Red Fairy'.
Rose breeders quickly saw the value in crossing polyanthas with hybrid teas, to create roses that bloomed with the polyantha profusion, but with hybrid tea floral beauty and color range. In 1909, the first polyantha/hybrid tea cross, 'Gruss an Aachen,' was created, with characteristics midway between both parent classes. As the larger, more shapely flowers and hybrid-tea-like growth habit separated these new roses from polyanthas and hybrid teas alike, a new class was created and named Floribunda, Latin for "many-flowering." Typical floribundas feature stiff shrubs, smaller and bushier than the average hybrid tea but less dense and sprawling than the average polyantha. The flowers are often smaller than hybrid teas but are carried in large sprays, giving a better floral effect in the garden. Floribundas are found in all hybrid tea colors and with the classic hybrid tea-shaped blossom, sometimes differing from hybrid teas only in their cluster-flowering habit. Today they are still used in large bedding schemes in public parks and similar spaces. Examples: 'Dainty Maid', 'Iceberg', 'Tuscan Sun'.
Grandifloras (Latin for "large-flowered") were the class of roses created in the mid 1900s to designate back-crosses between hybrid teas and floribundas that fit neither category — specifically, the 'Queen Elizabeth' rose, which was introduced in 1954. Grandiflora shrubs are typically larger than either hybrid teas or floribundas, and feature hybrid tea-style flowers borne in small clusters of three to five, similar to a floribunda. Grandifloras maintained some popularity from about the 1950s to the 1980s but today they are much less popular than either the hybrid teas or the floribundas. Examples: 'Queen Elizabeth', 'Comanche,' 'Montezuma'.
All of the classes of Old Garden Roses—gallicas, centifolias, etc.—had corresponding miniature forms, although these were once-flowering just as their larger forms were. As with the standard-sized varieties, miniature Old Garden roses were crossed with repeat-blooming Asian species to produce everblooming miniature roses. Today, miniature roses are represented by twiggy, repeat-flowering shrubs ranging from 6" to 36" in height, with most falling in the 12"–24" height range. Blooms come in all the hybrid tea colours; many varieties also emulate the classic high-centered hybrid tea flower shape. Miniature roses are often marketed and sold by the floral industry as houseplants, but it is important to remember that these plants are largely descended from outdoor shrubs native to temperate regions; thus, most miniature rose varieties require an annual period of cold dormancy to survive. (Examples: Petite de Hollande (Miniature Centifolia, once-blooming), Cupcake (Modern Miniature, repeat-blooming).)
As is the case with Miniature roses, all aforementioned classes of roses, both Old and Modern, have "climbing" forms, whereby the canes of the shrubs grow much longer and more flexible than the normal ("bush") forms. In the Old Garden Roses, this is often simply the natural growth habit of many cultivars and varieties; in many Modern roses, however, climbing roses are the results of spontaneous mutations. For example, 'Climbing Peace' is designated as a "Climbing Hybrid Tea," for it is genetically identical to the normal "shrub" form of the 'Peace' hybrid tea rose, except that its canes are long and flexible, i.e. "climbing." Most Climbing roses grow anywhere from 8'–20' in height and exhibit repeat-bloom. Rambler roses, although technically a separate class, are often lumped together with climbing roses. They also exhibit long, flexible canes, but are distinguished from true climbers in two ways: A larger overall size (20'–30' tall is common), and a once-blooming habit. It should be noted that both climbing roses and rambling roses are not true vines such as ivy,clematis or wisteria; they lack the ability to cling to supports on their own, and must be manually trained and tied over structures such as arbors and pergolas. Examples: 'Blaze' (repeat-blooming climber), 'American Pillar' (once-blooming rambler).
Although not officially recognized as a separate class of roses by any established rose authority, English (aka David Austin) roses are often set aside as such by consumers and retailers alike. Development started in the 1960s by David Austin of Shropshire,England, who wanted to rekindle interest in Old Garden Roses by hybridizing them with modern hybrid teas and floribundas. The idea was to create a new group of roses that featured blooms with old-fashioned shapes and fragrances, evocative of classic gallica, alba and damask roses, but with modern repeat-blooming characteristics and the larger modern color range as well. Austin mostly succeeded in his mission; his tribe of "English" roses, now numbering hundreds of varieties, has been warmly embraced by the gardening public and are widely available to consumers. David Austin roses are still actively developed, with new varieties released regularly. It should be noted that the typical winterhardiness and disease-resistance of the classic Old Garden Roses has largely been compromised in the process; many English roses are susceptible to the same disease problems that plague modern hybrid teas and floribundas, and many are not hardy north of USDA Zone 5. Examples: 'Mary Rose,' 'Graham Thomas', 'Tamora'.
Developed for the extreme weather conditions of Canadian winters, these roses were developed by Agriculture Canada at the Morden Research Station in Morden, Manitoba and the Experimental Farm in Ottawa (and later at L'Assomption, Quebec). These two main lines are called the Parkland series and the Explorer series. These programs have now been discontinued; however the remaining plant stock has been taken over by private breeders via the Canadian Artists series. Derived mostly from crosses of native Canadian species and more tender roses, these plants are extremely tolerant of cold weather, some down to -50F. A wide diversity of forms and colors were achieved. Examples include 'Morden Belle', 'Winnipeg Parks' and 'Cuthbert Grant'.
Other notable Canadian breeders include Georges Bugnet and Robert Erskine. These are a modern classifation of rose developed mainly for mass amenity planting. They are collectively known as shrub roses. In the late 20th century, traditional hybrid tea and floribunda rose varieties fell out of favor amid gardeners and landscapers, as they are often labor- and chemical-intensive plants susceptible to myriad pest and disease problems. So-called "landscape" roses have thus been developed to fill the consumer desire for a garden rose that offers color, form and fragrance, but is also low maintenance and easy to care for. Most landscape roses having the following characteristics:
Good disease resistance
Lower growing habit, usually under 60 cm (24 in)
Repeat flowering
Disease and pest resistance
Non suckering, growing on their own roots.
Principal parties involved in the breeding of new Landscape Roses varieties are: Werner Noak (Germany), Meidiland Roses (France), Boot & Co. (Netherlands), and William Radler (USA).
Rose pruning, sometimes regarded as a horticultural art form, is largely dependent on the type of rose to be pruned, the reason for pruning, and the time of year it is at the time of the desired pruning.
Most Old Garden Roses of strict European heritage (albas, damasks, gallicas, etc.) are shrubs that bloom once yearly, in late spring or early summer, on two-year-old (or older) canes. As such, their pruning requirements are quite minimal, and are overall similar to any other analogous shrub, such as lilac or forsythia. Generally, only old, spindly canes should be pruned away, to make room for new canes. One-year-old canes should never be pruned because doing so will remove next year's flower buds. The shrubs can also be pruned back lightly, immediately after the blooms fade, to reduce the overall height or width of the plant. In general, pruning requirements for OGRs are much less laborious and regimented than for Modern hybrids.
Modern hybrids, including the hybrid teas, floribundas, grandifloras, modern miniatures, and English roses, have a complex genetic background that almost always includes China roses (R. chinensis). China roses were evergrowing, everblooming roses from humid subtropical regions that bloomed constantly on any new vegetative growth produced during the growing season. Their modern hybrid descendants exhibit similar habits: Unlike Old Garden Roses, modern hybrids bloom continuously (until stopped by frost) on any new canes produced during the growing season. They therefore require pruning away of any spent flowering stem, in order to divert the plant's energy into producing new growth and thence new flowers.
Additionally, Modern Hybrids planted in cold-winter climates will almost universally require a "hard" annual pruning (reducing all canes to 8"–12" in height) in early spring. Again, because of their complex China rose background, Modern Hybrids are typically not as cold-hardy as European OGRs, and low winter temperatures often desiccate or kill exposed canes. In spring, if left unpruned, these damanged canes will often die back all the way to the shrub's root zone, resulting in a weakened, disfigured plant. The annual "hard" pruning of hybrid teas, floribundas, etc. should generally be done in early spring; most gardeners coincide this pruning with the blooming of forsythia shrubs. Canes should be cut about 1/2" above a vegetative bud (identifiable as a point on a cane where a leaf once grew).
For both Old Garden Roses and Modern Hybrids, any weak, damaged or diseased growth should be pruned away completely, regardless of the time of year. Any pruning of any rose should also be done so that the cut is made at a forty five degree angle above a vegetative bud. This helps the pruned stem callus over more quickly, and also mitigates moisture buildup over the cut, which can lead to disease problems.
For all general rose pruning (including cutting flowers for arrangements), sharp secateurs (hand-held, sickle-bladed pruners) should be used to cut any growth 1/2" or less in diameter. For canes of a thickness greater than 1/2", pole loppers or a small handsaw are generally more effective; secateurs may be damaged or broken in such instances.
Deadheading is the simple practice of manually removing any spent, faded, withered, or discoloured flowers from rose shrubs over the course of the blooming season. The purpose of deadheading is to encourage the plant to focus its energy and resources on forming new offshoots and blooms, rather than in fruit production. Deadheading may also be performed, if spent flowers are unsightly, for aethestic purposes. Roses are particularly responsive to deadheading.
Deadheading causes different effects on different varieties of roses. For continual blooming varieties, whether Old Garden roses or more modern hybrid varieties, deadheading allows the rose plant to continue forming new shoots, leaves, and blooms. For "once-blooming" varieties (that bloom only once each season), deadheading has the effect of causing the plant to form new green growth, even though new blooms will not form until the next blooming season. For most rose gardeners, deadheading is used to refresh the growth of the rose plants to keep the rose plants strong, vibrant, and productive.
The rose has always been valued for its beauty and has a long history of symbolism. The ancient Greeks and Romans identified the rose with their goddesses of love referred to as Aphrodite and Venus. In Rome a wild rose would be placed on the door of a room where secret or confidential matters were discussed. The phrase sub rosa, or "under the rose", means to keep a secret — derived from this ancient Roman practice.
Early Christians identified the five petals of the rose with the five wounds of Christ. Despite this interpretation, their leaders were hesitant to adopt it because of its association with Roman excesses and pagan ritual. The red rose was eventually adopted as a symbol of the blood of the Christian martyrs. Roses also later came to be associated with the Virgin Mary.
Rose culture came into its own in Europe in the 1800s with the introduction of perpetual blooming roses from China. There are currently thousands of varieties of roses developed for bloom shape, size, fragrance and even for lack of prickles.
Roses are ancient symbols of love and beauty. The rose was sacred to a number of goddesses (including Isis and Aphrodite), and is often used as a symbol of the Virgin Mary. 'Rose' means pink or red in a variety of languages (such as Romance languages,Greek, and Polish).
The rose is the national flower of England and the United States, as well as being the symbol of England Rugby, and of the Rugby Football Union. It is also the provincial flower of Yorkshire and Lancashire in England (the white rose and red rose respectively), of Alberta (the wild rose) in Canada, and of Islamabad Capital Territory in Pakistan. It is the state flower of four US states: Iowa and North Dakota (R.arkansana),Georgia (R.laevigata), and New York (Rosa generally). Portland, Oregon counts "City of Roses" among its nicknames, and holds an annual Rose Festival.
Roses are occasionally the basis of design for rose windows, such windows comprising five or ten segments (the five petals and five sepals of a rose) or multiples thereof; however most Gothic rose windows are much more elaborate and were probably based originally on the wheel and other symbolism.
A red rose (often held in a hand) is a symbol of socialism or social democracy; it is also used as a symbol by the British and Irish Labour Parties, as well as by the French, Spanish (Spanish Socialist Workers' Party), Portuguese, Norwegian, Danish, Swedish, Finnish, Brazilian, Dutch (Partij van de Arbeid) and European socialist or social democratic parties. This originated when the red rose was used as a badge by the marchers in the May 1968 street protests in Paris.The White Rose was a World War II non violent resistance group in Germany.
Roses are often portrayed by artists. The French artist Pierre-Joseph Redoute produced some of the most detailed paintings of roses.
Henri Fantin-Latour was also a prolific painter of still life, particularly flowers including roses. The Rose 'Fantin-Latour' was named after the artist.
Other impressionists including Claude Monet and Paul Cezanne have paintings of roses among their works. Rose perfumes are made from attar of roses or rose oil, which is a mixture of volatile essential oils obtained by steam distilling the crushed petals of roses. The technique originated in Persia (the word Rose itself is from Persian) then spread through Arabia and India, but nowadays about 70% to 80% of production is in the rose valley near Kazanluk in Bulgaria, with some production in Qamsar in Iran and Germany. The Kaaba in Mecca is annually washed by the Iranian rose water from Qamsar. In Bulgaria, Iran and Germany, damask roses (Rosa damascena 'Trigintipetala') are used. In the French rose oil industry Rosa centifolia is used. The oil, pale yellow or yellow-grey in color, is sometimes called 'Rose Absolute' oil to distinguish it from diluted versions. The weight of oil extracted is about one three-thousandth to one six-thousandth of the weight of the flowers; for example, about two thousand flowers are required to produce one gram of oil.
The main constituents of attar of roses are the fragrant alcohols geraniol and l-citronellol; and rose camphor, an odourless paraffin. β-Damascenone is also a significant contributor to the scent.