''Chaetachme'' is a monotypic genus of flowering plants native to eastern and western Africa, including

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

, containing the single species ''Chaetachme aristata''. Its

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

common name is thorny elm, and it is known as ''muyuyu'' in

Kikuyu Kikuyu or Gikuyu (Gĩkũyũ) mostly refers to an ethnic group in Kenya or its associated language. It may also refer to: * Kikuyu people, a majority ethnic group in Kenya *Kikuyu language, the language of Kikuyu people *Kikuyu, Kenya, a town in Cent ...

. Traditionally placed in the Elm family, it is more recently placed in 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 genera, including ''Cannabis'' (hemp), '' Humulus'' (hops) and '' Celtis'' (hackberries ...

, thought to be possibly closely related to ''

Celtis ''Celtis'' is a genus of about 60–70 species of deciduous trees, commonly known as hackberries or nettle trees, widespread in warm temperate regions of the Northern Hemisphere. The genus is part of the extended hemp family (Cannabaceae). De ...

''. ''Chaetachme aristata'' is a

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

or small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

growing up to 10 meters tall. It has drooping, angular branches covered with spines up to 3.5 centimeters in length. The lance-shaped leaves are up to 11 centimeters long by 5 centimeters wide, pointed at the tip and smooth or serrated on the edges. The shrub is

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 reproductio ...

and

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

, with male and female flower types borne on separate individuals, although it may also be

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy is conne ...

. This shrub is host to the mirid bug '' Volumnus chaetacme''. The spiny branches of the shrub are used as

fence A fence is a structure that encloses an area, typically outdoors, and is usually constructed from posts that are connected by boards, wire, rails or netting. A fence differs from a wall in not having a solid foundation along its whole length. ...

s in African villages.Bussmann, R. W., et al. (2006)
Plant use of the Maasai of Sekenani Valley, Maasai Mara, Kenya.
''J Ethnobiol Ethnomed'' 2 22.

References

Cannabaceae Monotypic Rosales genera Flora of Africa {{Rosales-stub