Cannabaceae
Encyclopedia
Cannabaceae are a small family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

s. As now circumscribed
Circumscription (taxonomy)
In taxonomy, circumscription is the definition of the limits of a taxonomic group of organisms. One goal of taxonomy is to achieve a stable circumscription for every taxonomic group. Achieving stability can be simple or difficult....

, the family includes about 170 species grouped in about 11 genera, including Cannabis
Cannabis
Cannabis is a genus of flowering plants that includes three putative species, Cannabis sativa, Cannabis indica, and Cannabis ruderalis. These three taxa are indigenous to Central Asia, and South Asia. Cannabis has long been used for fibre , for seed and seed oils, for medicinal purposes, and as a...

(hemp), Humulus
Hop (plant)
Humulus, Hop, is a small genus of flowering plants native to temperate regions of the Northern Hemisphere. The female flowers of H. lupulus are known as hops, and are used as a culinary flavoring and stabilizer, especially in the brewing of beer...

(hops) and Celtis (hackberries). Celtis is by far the largest genus, containing about 100 species.

Other than their common evolutionary origin (see Phylogeny below), members of the family have few common characteristics; some are trees (e.g. Celtis), others are herbs
Herbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...

 (e.g. Cannabis).

Description

Cannabaceae are very similar to Moraceae
Moraceae
Moraceae — often called the mulberry family or fig family — are a family of flowering plants comprising about 40 genera and over 1000 species. Most are widespread in tropical and subtropical regions, less so in temperate climates...

. Members of this family can be trees (e.g. Celtis), erect (e.g. Cannabis
Cannabis
Cannabis is a genus of flowering plants that includes three putative species, Cannabis sativa, Cannabis indica, and Cannabis ruderalis. These three taxa are indigenous to Central Asia, and South Asia. Cannabis has long been used for fibre , for seed and seed oils, for medicinal purposes, and as a...

), or twining herbs (e.g. Humulus).

Leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

are often more or less palmately lobed or palmately compound and always bear stipule
Stipule
In botany, stipule is a term coined by Linnaeus which refers to outgrowths borne on either side of the base of a leafstalk...

s. Cystolith
Cystolith
Cystolith is a botanical term for the inorganic concretions, usually of calcium carbonate, formed in a cellulose matrix in special cells, generally in the leaf of plants of certain families, e.g. Ficus elastica, the Indian rubber plant of the family Moraceae...

s are always present and some members of this family possess laticifer
Laticifer
A laticifer is a type of elongated secretory cell found in the leaves and/or stems of plants that produce latex and rubber as secondary metabolites. Laticifers may be articulated, i.e., composed of a series of cells joined together, or non-articulated, consisting of one long cell...

s.

Cannabaceae are often dioecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....

 (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 is short and there is no corolla. Flowers are grouped to form cymes. In the dioecious plants the masculine inflorescences are long and look like panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....

s, while the feminine are shorter and bear less flowers. The pistil is made of two connate carpels, the usually superior ovary is unilocular; there is no fixed number of stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...

s.

The fruit can be an achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...

, drupe
Drupe
In botany, a drupe is a fruit in which an outer fleshy part surrounds a shell of hardened endocarp with a seed inside. These fruits develop from a single carpel, and mostly from flowers with superior ovaries...

 or a small nut
Nut (fruit)
A nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts...

.

Phylogeny

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
Angiosperm Phylogeny Group
The Angiosperm Phylogeny Group, or APG, refers to an informal international group of systematic botanists who came together to try to establish a consensus on the taxonomy of flowering plants that would reflect new knowledge about plant relationships discovered through phylogenetic studies., three...

 in 1998, they were placed in an expanded Rosales, forming a group which has been called "urticalean rosids".

A molecular phylogenetic study in 2002 produced the consensus tree shown below. This showed that the family Celtidaceae was paraphyletic
Paraphyly
A group of taxa is said to be paraphyletic if the group consists of all the descendants of a hypothetical closest common ancestor minus one or more monophyletic groups of descendants...

 if the Cannabaceae, as then circumscribed, were removed. Accordingly a single larger family was required, combining the two existing families. Under the rules of the International Code of Nomenclature for algae, fungi, and plants
International Code of Nomenclature for algae, fungi, and plants
The International Code of Nomenclature for algae, fungi, and plants is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "traditionally treated as plants"., Preamble, para...

, the oldest family name must be used: this is Cannabaceae.

List of genera

The following genera are listed by the Angiosperm Phylogeny Website, :
  • Aphananthe Planchon (syn. Mirandaceltis Sharp)
  • Cannabis
    Cannabis
    Cannabis is a genus of flowering plants that includes three putative species, Cannabis sativa, Cannabis indica, and Cannabis ruderalis. These three taxa are indigenous to Central Asia, and South Asia. Cannabis has long been used for fibre , for seed and seed oils, for medicinal purposes, and as a...

    L. – Hemp
  • Celtis L. (syn. Sparrea Hunz. & Dottori)
  • Gironniera Gaudich. (syn. Helminthospermum Thwaites, Nematostigma Planchon)
  • Humulus L. (syn. Humulopsis Grudz.) – Hop
  • Lozanella Greenman
  • Parasponia Miquel
  • Pteroceltis Maxim.
  • Trema
    Trema
    Trema is a genus of about 15 species of evergreen trees closely related to the hackberries , occurring in subtropical and tropical regions of southern Asia, northern Australasia, Africa, South and Central America, and parts of North America...

    Loureiro (syn. Sponia Decaisne)

Uses

Hop
Humulus lupulus
Humulus lupulus is a species of Humulus in the Cannabaceae family.Common hop is a dioecious, perennial herbaceous climbing plant which sends up new shoots in early spring and dies back to the cold-hardy rhizome in autumn...

 (Humulus lupulus) is cultivated for its fruits which contain aromatic substances used in the production of beer
Beer
Beer is the world's most widely consumed andprobably oldest alcoholic beverage; it is the third most popular drink overall, after water and tea. It is produced by the brewing and fermentation of sugars, mainly derived from malted cereal grains, most commonly malted barley and malted wheat...

. Its young shoots are used as vegetable. Different subspecies of hemp
Hemp
Hemp is mostly used as a name for low tetrahydrocannabinol strains of the plant Cannabis sativa, of fiber and/or oilseed varieties. In modern times, hemp has been used for industrial purposes including paper, textiles, biodegradable plastics, construction, health food and fuel with modest...

 (Cannabis sativa) are cultivated for the production of fiber, as a source of cheap oil
Hemp oil
Hempseed oil is pressed from the seed of the hemp plant irrespective of the strain of cannabis. Cold pressed, unrefined hemp oil is dark to clear light green in color, with a pleasant nutty flavor. The darker the color, the grassier the flavour....

, for the nutritious seeds, or to produce recreational, sacramental or medical cannabis
Cannabis (drug)
Cannabis, also known as marijuana among many other names, refers to any number of preparations of the Cannabis plant intended for use as a psychoactive drug or for medicinal purposes. The English term marijuana comes from the Mexican Spanish word marihuana...

.

Both hops and cannabis contain antimicrobial substances. This is why hops extract is used in natural deodorants. Cannabinoids in cannabis are effective at killing MRSA
Methicillin-resistant Staphylococcus aureus
Methicillin-resistant Staphylococcus aureus is a bacterium responsible for several difficult-to-treat infections in humans. It is also called multidrug-resistant Staphylococcus aureus and oxacillin-resistant Staphylococcus aureus...

, a drug-resistant bacteria.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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