Cannabaceae is a small

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants t ...

s, known as the hemp family. As now circumscribed, the family includes about 170 species grouped in about 11 genera, including ''

Cannabis ''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''. Alternative ...

'' (hemp), '' Humulus'' (

hops Hops are the flowers (also called seed cones or strobiles) of the hop plant '' Humulus lupulus'', a member of the Cannabaceae family of flowering plants. They are used primarily as a bittering, flavouring, and stability agent in beer, to w ...

) and '' Celtis'' (hackberries). ''Celtis'' is by far the largest genus, containing about 100 species.Stevens, P.F. (2001 onwards
"Cannabaceae"
''Angiosperm Phylogeny Website'', retrieved 2014-02-25 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. Other than a shared evolutionary origin, members of the family have few common characteristics; some are trees (e.g. ''Celtis''), others are

herbaceous plant Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition ...

s (e.g. ''Cannabis'').

Description

Members of this family can be trees (e.g. '' Celtis''), erect herbs (e.g. ''

''), or twining herbs (e.g. '' Humulus''). Leaves are often more or less palmately lobed or palmately compound and always bear

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

Cystolith Cystolith (Gr. "cavity" and "stone") is a botanical term for outgrowths of the epidermal cell wall, usually of calcium carbonate, formed in a cellulose matrix in special cells called lithocysts, generally in the leaf of plants. Cystoliths are pr ...

s are always present and some members of this family possess

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 divided into: *Articulated laticifers, i.e., composed of a series of cells joined ...

s. Cannabaceae are often

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproducti ...

(distinct male and female plants). The flowers are

actinomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spirall ...

(radially symmetrical) and not showy, as these plants are pollinated by the wind. As an adaptation to this kind of pollination, the

calyx Calyx or calyce (plural "calyces"), from the Latin ''calix'' which itself comes from the Ancient Greek ''κάλυξ'' (''kálux'') meaning "husk" or "pod", may refer to: Biology * Calyx (anatomy), collective name for several cup-like structures ...

and

corolla Corolla may refer to: *Corolla (botany), the petals of a flower, considered as a unit *Toyota Corolla, an automobile model name *Corolla (headgear) A ''corolla'' is an ancient headdress in the form of a small circlet or crown.cymes An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...

. In the dioecious plants the male inflorescences are long and look like

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

s, while the female ones are shorter and bear fewer flowers. The

pistil Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) '' pistils ...

is made of two connate

carpel Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) '' pistils' ...

s, the usually superior ovary is unilocular; there is no fixed number of

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the fila ...

s. The fruit can be an

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not o ...

or a

drupe In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part ( exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or ''pyrena'') of hardened endocarp with a seed (''kernel ...

Taxonomy

Classification

Classification systems developed prior to the 1990s, such as those of Cronquist (1981) and Dahlgren (1989), typically recognized the order

Urticales 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. A ...

, 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 The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships disc ...

in 1998, they were placed in an expanded Rosales, forming a group which has been called 'urticalean rosids'. Hopfen3

Cannabaceae comprises the following genera: * ''

Aphananthe ''Aphananthe'' is a small genus of evergreen trees in the family Cannabaceae. Around six species are recognised, found in Madagascar, South-east Asia, Mexico and Australia. Leaves are alternate on the stem and toothed. Flowers are unisexual, ...

'' Planch. (5 spp.) * ''

'' —Hemp (3 spp.) * '' Celtis'' L. (73–109 spp.) * ''

Chaetachme ''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 Ki ...

'' Planch. (1 sp.) * ''

Gironniera ''Gironniera'', is a genus of deciduous trees, containing six recognized species. It is widespread in tropical countries. Species *'' Gironniera celtidifolia'' Gaudich. *'' Gironniera hirta'' Ridl. *'' Gironniera nervosa'' Planch. *'' Giron ...

'' Gaudich. (6 spp.) * '' Humulus'' L.—Hop (3 spp.) * ''

Lozanella ''Lozanella'' is a genus of flowering plants belonging to the family Cannabaceae 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 gene ...

'' Greenm. (2 spp.) * '' Parasponia'' Miq. (5–10 spp.) * ''

Pteroceltis ''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 include ...

'' Maxim. (1 sp.) * ''

Trema Trema may refer to: * a Greek and Latin root meaning ''hole'' * ''Tréma'', a word in French meaning diaeresis ** more generally, two dots (diacritic) * ''Trema'' (plant), a genus of about 15 species of small evergreen trees * Tréma (record la ...

'' Lour. (12–42 spp.)

Phylogeny

Cannabaceae likely originated in East Asia during the Late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

. The oldest known pollen typical of members of Cannabaceae is from the Late Cretaceous (

Turonian The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded b ...

~94–90 million years ago) of

Sarawak Sarawak (; ) is a state of Malaysia. The largest among the 13 states, with an area almost equal to that of Peninsular Malaysia, Sarawak is located in northwest Borneo Island, and is bordered by the Malaysian state of Sabah to the northeast, ...

, 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. Modern

molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

suggest the following relationships:

Uses

Carbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was de ...

has revealed that these plants may have been used for ritual/medicinal purposes in Xinjiang, China as early as 494 B.C. ''

Humulus lupulus ''Humulus lupulus'', the common hop or hops, is a species of flowering plant in the hemp family Cannabinaceae, native to Europe, western Asia and North America. It is a perennial, herbaceous climbing plant which sends up new shoots in early s ...

'', the common hop, has been the predominant bittering agent of

beer Beer is one of the oldest and the most widely consumed type of alcoholic drink in the world, and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from ce ...

for hundreds of years. The flowers' resins are responsible for beer's bitterness and their ability to extend shelf life due to some

antimicrobial An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ar ...

qualities. The young shoots are used as vegetable. Some plants in the genus ''Cannabis'' are cultivated as

hemp Hemp, or industrial hemp, is a botanical class of '' Cannabis sativa'' cultivars grown specifically for industrial or medicinal use. It can be used to make a wide range of products. Along with bamboo, hemp is among the fastest growing plants ...

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 botany and horticulture, parthenocarpy is the natural or artificially induced production of fruit without fertilisation of ovules, which makes the fruit seedless. Stenospermocarpy may also produce apparently seedless fruit, but the seeds ar ...

in pistilate flowers, and

selective breeding Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant ...

are used to produce either higher or lower yields of

tetrahydrocannabinol Tetrahydrocannabinol (THC) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers, the term ''THC' ...

(THC), other

cannabinoid Cannabinoids () are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tet ...

s, 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

is used to produce high-end Chinese rice paper.

References

External links

Cannabaceae of Mongolia in FloraGREIF
{{Authority control Rosid families Extant Turonian first appearances