[Greek thes, laboring servant, alluding to simple appearance] [Greek thes, laboring servant, alluding to simple appearance]

Herbs [shrubs], perennial [annual], synoecious [dioecious]. Stems erect, hairy [glabrous]. Leaves alternate [opposite]. Inflorescences racemelike [spikelike] thyrses; flowers subtended by bract and 2 bracteoles [bract absent]. Pedicels absent [present]. Flowers bisexual [unisexual]; hypanthium adnate to ovary proximally, free distally; sepals 0 [present as small lobes or glands]; petals (4–)5, post-staminal hairs present; nectary lining hypanthium; stamens (4–)5; ovules 2–3 per locule; stigma capitate. Pseudodrupes: exocarp leathery; pedicel enlarging and becoming fleshy; hypanthium and petals persistent. x = 6–9.

Species 366 (1 in the flora): introduced; nearly worldwide.

Thesium is closely related to the South African endemic Osyridocarpos A. de Candolle (J. P. Der and D. L. Nickrent 2008). For this reason and because Africa contains the highest species diversity, this region can be assumed to be the center of origin for Thesium.

Lower Taxon

• Thesium ramosum Hayne