S. Holmes (1993) 1:306-337

Plants  trees, shrubs, or herbs, fleshy or succulent, unarmed or spiny, usually moneocious, rarely dioecious; latex present, often caustic. Roots fibrous or thick and fleshy, sometimes tuberous. Leaves usually alternate, sometimes opposite or whorled, often stipulate, subtended by spiny outgrowths in some succulent species; stipules absent or modified as glands, scales, or spines. Inflorescences terminal or axillary, composed of solitary or clustered cyathia, clusters cymose, the cymes sometimes forming false umbels or dichotomously branching; bracts paired, free or partly united along one edge to form bract-cups, often leaflike, sometimes brightly colored and showy; involucres with (1-)4-5(-8) glands around the rim alternating or surrounding fringed lobes, the glands sometimes forming a horseshoe shaped ring. Male flowers in 5 groups,, each with a fringed membrane [bracteole]. Female flowers subsessile, the pedicel usually elongating and recurved in fruit but straightening before dehiscence; perianth usually a rim below the 3-celled ovary, occasionally 3-lobed; styles 3, partly united; stigmas sometimes bifid. Fruits capsules, often 3-lobed, sometimes initially fleshy but hardening at maturity, loculidally and septicidally dehiscent; seeds with or without a caruncle. 

Euphorbia is now interpreted as including Monadenium, a taxon treated as a distinct genus in the Flora of Somalia. It has long been regarded as one of the largest genera of flowering plants; this has not changed. It is now interpreted as having up to 2000 species distributed around the world in temperate, tropical, and subtropical regions. About 1300 species are herbaceous. The arborescent, shrubby, and succulent species are confined almost entirely to the tropics and subtropics. with most of the succulent species growing in the drier regions of Africa and Madagascar. There are 107 species in Somaliland and Somalia. This includes those that the Flora includes in Monadenium.

Key to the subgenera present in Somaliland and Somalia.

Global distribution of Euphorbia based on specimens records provided to GBIF