Cannabaceae Temporal range: | |
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Cannabis sativa | |
'Aurea' Humulus lupulus (Hops) | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Rosales |
Family: | Cannabaceae Martinov [2] [3] |
Genera | |
See text | |
Synonyms [3] | |
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Cannabaceae is a small family of flowering plants, known as the hemp family. As now circumscribed, the family includes about 170 species grouped in about 11 genera, including Cannabis (hemp), Humulus (hops) and Celtis (hackberries). Celtis is by far the largest genus, containing about 100 species. [2]
Cannabaceae is a member of the Rosales. Members of the family are erect or climbing plants with petalless flowers and dry, one-seeded fruits. Hemp (Cannabis) and hop (Humulus) are the most economically important species. [4]
Other than a shared evolutionary origin, members of the family have few common characteristics; some are trees (e.g. Celtis), others are herbaceous plants (e.g. Cannabis).
Members of this family can be trees (e.g. Celtis ), erect herbs (e.g. Cannabis ), or twining herbs (e.g. Humulus ). [2]
Leaves are often more or less palmately lobed or palmately compound and always bear stipules. Cystoliths are always present and some members of this family possess laticifers.
Cannabaceae are often dioecious (distinct male and female plants). The flowers are actinomorphic (radially symmetrical) and not showy, as these plants are pollinated by the wind. As an adaptation to this kind of pollination, the calyx and corolla are radically reduced to only vestigial remnants found as an adherent perianth coating the seed. A reduced and monophyllous cuplike perigonal bract, properly known as the bracteole, immediately surrounds and protects the seed and is often misnamed as a "calyx". Flowers are grouped to form cymes. In the dioecious plants the male inflorescences are long and look like panicles, while the female ones are shorter and bear fewer flowers. The pistil is made of two connate carpels, the usually superior ovary is unilocular; there is no fixed number of stamens.
The fruit can be an achene or a drupe.
Classification systems developed prior to the 1990s, such as those of Cronquist (1981) and Dahlgren (1989), typically recognized the order Urticales, which included the families Cannabaceae, Cecropiaceae, Celtidaceae, Moraceae, Ulmaceae and Urticaceae, as then circumscribed. Molecular data from 1990s onwards showed that these families were actually embedded within the order Rosales, so that from the first classification by the Angiosperm Phylogeny Group in 1998, they were placed in an expanded Rosales, forming a group which has been called 'urticalean rosids'. [3]
Cannabaceae comprises the following genera: [5] [6] [7]
Cannabaceae likely originated in East Asia during the Late Cretaceous. The oldest known pollen typical of members of Cannabaceae is from the Late Cretaceous (Turonian ~94–90 million years ago) of Sarawak, Borneo. Fossils show Cannabaceae were widely distributed in the Northern Hemisphere during the early Cenozoic, though their distribution shifted towards tropical regions in the later Cenozoic due to changing climates. [8]
Modern molecular phylogenetics suggest the following relationships: [3] [9] [10] [5]
Cladogram of Cannabaceae genera | |||||||||||||||||||||||||||||||||||||||||||||
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Carbon dating has revealed that these plants may have been used for ritual/medicinal purposes in Xinjiang, China as early as 494 B.C. [11]
Humulus lupulus , the common hop, has been the predominant bittering agent of beer for hundreds of years. The flowers' resins are responsible for beer's bitterness and their ability to extend shelf life due to some antimicrobial qualities. The young shoots can be used as a vegetable. [12]
Some plants in the genus Cannabis are cultivated as hemp for the production of fiber, as a source of cheap oil, for their nutritious seeds, or their edible leaves. Others are cultivated for medical or recreational use as dried flowers, extracts, or infused food products. Induced parthenocarpy in pistilate flowers, and selective breeding are used to produce either higher or lower yields of tetrahydrocannabinol (THC), other cannabinoids, as well as terpenes with desired flavors or aromas, such as blueberry, strawberry, or even citrus.
Many trees in the genus Celtis are grown for landscaping and ornamental purposes, and the bark of Pteroceltis is used to produce high-end Chinese rice paper.
The Cucurbitaceae, also called cucurbits or the gourd family, are a plant family consisting of about 965 species in 101 genera. Those of most agricultural, commercial or nutritional value to humans include:
The Malpighiales comprise one of the largest orders of flowering plants, containing about 36 families and more than 16,000 species, about 7.8% of the eudicots. The order is very diverse, containing plants as different as the willow, violet, poinsettia, manchineel, rafflesia and coca plant, and are hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification systems based only on plant morphology. Molecular clock calculations estimate the origin of stem group Malpighiales at around 100 million years ago (Mya) and the origin of crown group Malpighiales at about 90 Mya.
Rosales is an order of flowering plants. It is sister to a clade consisting of Fagales and Cucurbitales. It contains about 7,700 species, distributed into about 260 genera. Rosales comprise nine families, the type family being the rose family, Rosaceae. The largest of these families are Rosaceae (91/4828) and Urticaceae (53/2625). The order Rosales is divided into three clades that have never been assigned a taxonomic rank. The basal clade consists of the family Rosaceae; another clade consists of four families, including Rhamnaceae; and the third clade consists of the four urticalean families.
Cannabis is a genus of flowering plants in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized: Cannabis sativa, C. indica, and C. ruderalis. Alternatively, C. ruderalis may be included within C. sativa, or all three may be treated as subspecies of C. sativa, or C. sativa may be accepted as a single undivided species. The genus is widely accepted as being indigenous to and originating from Asia.
The Vitaceae are a family of flowering plants, with 14 genera and around 910 known species, including common plants such as grapevines and Virginia creeper. The family name is derived from the genus Vitis.
The Moraceae—often called the mulberry family or fig family—are a family of flowering plants comprising about 38 genera and over 1100 species. Most are widespread in tropical and subtropical regions, less so in temperate climates; however, their distribution is cosmopolitan overall. The only synapomorphy within the Moraceae is presence of laticifers and milky sap in all parenchymatous tissues, but generally useful field characters include two carpels sometimes with one reduced, compound inconspicuous flowers, and compound fruits. The family includes well-known plants such as the fig, banyan, breadfruit, jackfruit, mulberry, and Osage orange. The 'flowers' of Moraceae are often pseudanthia.
Urticales is an order of flowering plants. Before molecular phylogenetics became an important part of plant taxonomy, Urticales was recognized in many, perhaps even most, systems of plant classification, with some variations in circumscription. Among these is the Cronquist system (1981), which placed the order in the subclass Hamamelidae [sic], as comprising:
The Araliaceae are a family of flowering plants composed of about 43 genera and around 1500 species consisting of primarily woody plants and some herbaceous plants commonly called the ginseng family. The morphology of Araliaceae varies widely, but it is predominantly distinguishable based on its woody habit, tropical distribution, and the presence of simple umbels.
The Urticaceae are a family, the nettle family, of flowering plants. The family name comes from the genus Urtica. The Urticaceae include a number of well-known and useful plants, including nettles in the genus Urtica, ramie, māmaki, and ajlai.
The Ulmaceae are a family of flowering plants that includes the elms, and the zelkovas. Members of the family are widely distributed throughout the north temperate zone, and have a scattered distribution elsewhere except for Australasia.
Celtis is a genus of about 60–70 species of deciduous trees, commonly known as hackberries or nettle trees, in the hemp family Cannabaceae. It has a cosmopolitan distribution.
Trema is a genus of about 15 species of evergreen trees closely related to the hackberries (Celtis), occurring in subtropical and tropical regions of southern Asia, northern Australasia, Africa, South and Central America, and parts of North America. They are generally small trees, reaching 10–20 m (33–66 ft) tall.
Saxifragaceae is a family of herbaceous perennial flowering plants, within the core eudicot order Saxifragales. The taxonomy of the family has been greatly revised and the scope much reduced in the era of molecular phylogenetic analysis. The family is divided into ten clades, with about 640 known species in about 35 accepted genera. About half of these consist of a single species, but about 400 of the species are in the type genus Saxifraga. The family is predominantly distributed in the northern hemisphere, but also in the Andes in South America.
Cunoniaceae is a family of 27 genera and about 335 species of woody plants in the order Oxalidales, mostly found in the tropical and wet temperate regions of the Southern Hemisphere. The greatest diversity of genera are in Australia and Tasmania, New Guinea, and New Caledonia. The family is also present in Central America, South America, the Caribbean, Malesia, the islands of the South Pacific, Madagascar and surrounding islands. The family is absent from mainland Asia except from Peninsular Malaysia, and almost absent from mainland Africa apart from two species from Southern Africa. Several of the genera have remarkable disjunct ranges, found on more than one continent, e.g. Cunonia, EucryphiaWeinmannia.
Humulus lupulus, the common hop or hops, is a species of flowering plant in the hemp family, Cannabaceae. It is a perennial, herbaceous climbing plant which sends up new shoots in early spring and dies back to a cold-hardy rhizome in autumn. It is dioecious and native to West Asia, Europe and North America.
Chaetachme is a monotypic genus of flowering plants native to eastern and western Africa, including Madagascar, containing the single species Chaetachme aristata. Its English common name is thorny elm, and it is known as muyuyu in Kikuyu. Traditionally placed in the Elm family, it is more recently placed in the family Cannabaceae, thought to be possibly closely related to Celtis.
Trema tomentosum, also known as T. tomentosa and commonly called poison peach, is a shrub or tree in the family Cannabaceae native to the Indian subcontinent, south east Asia, through the islands of the south west Pacific, and the east coast and northern half of Australia.
Pteroceltis is a genus of small trees in the family Cannabaceae and containing the living species Pteroceltis tatarinowii. The genus is now restricted to an endemic range in China and Mongolia. The genus has a fossil record which includes species described from Korea, Japan, Germany, and the United States.