Description:

• Annual herbs of tufted habit when young, later branching prostrately
• Leaves opposite, radical or clustered at ends of prostrate or decumbent branches, flat, petiolate, sheathing at base, not connate; tannin idioblasts in epidermis (only case known in family), surface covered with wax flakes
• Flowers mostly solitary, on elongate, erect pedicels becoming prostrate in fruit; opening in afternoon and closing at night
• Sepals 5
• Petals free or nearly so, ivory to yellow, fading to orange, epapillate
• Stamens epapillate; staminodes 0
• Nectary an inconspicuous, faintly crenulate ring
• Ovary basin-shaped with a depressed top, with a mushroom-shaped structure in the centre, formed by connate stigmas, with 8(12 papilla-like stigmatic surfaces on top; placentas axile
• Fruit a schizocarpic capsule, 8(12-locular; without opening devices but breaking up into flat, circular, broadly winged, 1-seeded units (clausae); dispersal anemochoric
• x = 9

• Flowering from spring to early summer

• Distinguishing characters:
  • Annual herbs with flat leaves
  • Flowers solitary, petals ivory to yellow, fading to reddish with age, stigmas forming a central column
  • Fruit schizocarpic

Nomenclature:

• Hymenogyne Haw.
  • Haworth: 192 (1821)
  • Herre: 176 (1971)
  • Ihlenfeldt & Gerbaulet: 457 (1990)
  • Gerbaulet & Ihlenfeldt: 511 (1990)
  • Smith et al.: 74 (1998)
• Thyrasperma N.E.Br.
  • Brown: 412 (1925)

Distribution & Notes:

• Southern Africa: Species 2, Western Cape, from the Cape Peninsula to Clanwilliam