The genus Euphorbia includes about two thousand species
scattered throughout the whole earth surface; many of them are
widespread in the dry and desert tropical and subtropical African
regions.
The spurges present a great morphological diversity: herbs,
shrubs, but also succulent plants. The aspect of the latter reminds the
cacti of the American deserts: columnar or globular trunks, smooth or
tubercolate trunks, the leaves reduced, rarefied or transformed into
thorns.
The flowers are small, wrapped up by glands, gathered in
characteristic inflorescences called "ciazi". Sometimes there are
multicolored and showy leaf bracts making evident this unusual flower
complex.
The spurges are known since ancient times (since 500 BC) for the medicinal, caustic, and poisonous properties of the latex.