Description :

• Parasitic or hemiparasitic annual or perennial herbs, shrubs or dwarf shrubs, usually glabrous
• Leaves alternate, linear, linear-lanceolate, subulate, scale-like or rarely suborbicular
• Inflorescence a loose or compact, terminal or axillary raceme, spike, or panicle, with leafy branches sometimes replacing flowers in axils of bracteoles
• Flowers bisexual
• Perianth : tube cup-shaped or tubular; lobes 5, spreading or erect, ± hooded, with or without an apical beard of hairs and usually with tuft of hairs adhering to apex of anthers; in absence of these hairs a ring of hairs occurs at throat of perianth tube at level of insertion of filaments; margins hairy, papillose or glabrous
• Stamens 5, arising at base of perianth lobes; anthers ovoid or oblong
• Disc often conspicuous
• Ovary 3-merous; ovules 2-4, pendulous from apex of slender, flexuose placenta; style cylindrical or almost absent; stigma capitate or obscurely 3-lobed
• Fruit an ellipsoid, globose or obovoid nut, usually 10-ribbed, crowned with persistent perianth
• Seed similar in shape to fruit; embryo central with fleshy endosperm, radicle as long as or longer than cotyledons
• x = 6, 7, 8 (2, 9, 10, 13)

Nomenclature:

• Thesium L.
  • Linnaeus: 207 (1753)
  • Linnaeus: 205 (1754)
  • Brown: 352 (1810)
  • Hill: 136 (1915)
  • Brown: 455 (1932)
  • Levyns: 332 (1950)
  • Roessler: 2 (1969)

Distribution & Notes:

• Global : Species ± 325, in temperate regions of the Old World, 2 in South America and many in Africa
• Southern Africa : Species over 180, widespread, particularly frequent in grassland