''Barbeya'' is the only

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Barbeyaceae, and has only one

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, ''Barbeya oleoides''. It is a small tree native to the mountains of

Somalia Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...

Ethiopia Ethiopia, officially the Federal Democratic Republic of Ethiopia, is a landlocked country located in the Horn of Africa region of East Africa. It shares borders with Eritrea to the north, Djibouti to the northeast, Somalia to the east, Ken ...

, and the

Arabian Peninsula The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world. Geographically, the ...

. It can be found locally abundant in the transition zone between the dry, evergreen,

Afromontane The Afromontane regions are subregions of the Afrotropical realm, one of the Earth's eight biogeographic realms, covering the plant and animal species found in the mountains of Africa and the southern Arabian Peninsula. The Afromontane regions o ...

forests and lower-elevation evergreen bushlands. ''Barbeya oleoides'' has opposite, oblong-lanceolate, simple leaves with entire margins. Plants are

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

, with male and female flowers on separate trees. The family Barbeyaceae is closely related to its ecological associate on the

Horn Horn may refer to: Common uses * Horn (acoustic), a tapered sound guide ** Horn antenna ** Horn loudspeaker ** Vehicle horn ** Train horn *Horn (anatomy), a pointed, bony projection on the head of various animals * Horn (instrument), a family ...

, the family

Dirachmaceae ''Dirachma'' is the sole genus of the family Dirachmaceae. The genus had been monotypic, its sole species being the woody plant '' Dirachma socotrana'', until a second, herbaceous, species, '' Dirachma somalensis'', was discovered in Somalia ...

. Evidence on the molecular level has demonstrated this despite obvious morphological differences between the two families such as Barbeya having small,

unisexual Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

, petalless

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s, while the flowers of Dirachmaceae are characterized by their

bisexuality Bisexuality is romantic attraction, sexual attraction, or Human sexual activity, sexual behavior toward both males and females. It may also be defined as the attraction to more than one gender, to people of both the same and different gender, ...

, and their relatively large

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s (and size in general).

References

Monotypic Rosales genera Rosales Somali montane xeric woodlands Southwestern Arabian foothills savanna Dioecious plants Flora of the Afrotropical realm {{Rosales-stub