Description:

• Dwarf, succulent perennials forming small, dense clumps or mats, up to 200 mm high; usually with a short woody rootstock, occasionally with fleshy roots
• Leaves often very unequal and variable in shape, connate to different degrees, forming ± spherical bodies or trigonous with an apical chin to digitiform; light to dark green, bluish green, reddish, metallic grey, whitish green or grey-white; epidermis minutely hairy or with long dense hairs, more rarely smooth; stomata, and in most cases, subsidiary cells, sunken
• Flowers solitary, terminal, pedicellate, ebracteate, 20(80 mm in diameter; opening in afternoon and closing in evening
• Sepals 6(9, unequal
• Petals 1(3-seriate, linear, free, white, pink, or different shades of purple
• Stamens: staminodes present or 0, often bearded at base
• Nectary of 6(?-9) large, separate, crenulate glands
• Ovary often somewhat conical; placentas parietal; stigmas 6(9, usually stout and subulate, plumose
• Fruit a 6(9-locular capsule, of Drosanthemum type; convex or conical with prominent sutures; valves deltoid, spreading, reflexed when expanded; expanding keels parallel or diverging, rarely toothed, terminating in broad wings; covering membranes present; closing bodies 0
• Seeds many in each locule, acutely ovoid, smooth
• x = 9 (polyploidy)

• Flowering from late winter to early summer

• Distinguishing characters:
  • Dwarf perennials
  • Leaves subequal to unequal united into bodies with an oblique fissure separating the leaves of a pair, often velvety
  • Flowers purple or white

Nomenclature:

• Gibbaeum Haw.
  • Haworth: 104 (1821)
  • Brown: 273 (1921)
  • Brown: 129, 151 (1922)
  • Nel: (1953)
  • Herre: 162 (1971)
  • Frandsen: 14 (1998)
  • Smith et al.: 104 (1998)
  • Van Jaarsveld & Hammer: 14 (1998)
• Imitaria N.E.Br.
  • Brown: 348 (1927c)
  • Herre: 178 (1971)
  • Hartmann: 1 (1993)
• Rimaria N.E.Br.
  • Brown: 413 (1925)
• Mentocalyx N.E.Br.
  • Brown: 251 (1927a)
• Argeta N.E.Br.
  • Brown: 113 (1927b)

Distribution & Notes:

• Southern Africa: Species 16, mostly found growing in the Little Karoo, Western Cape and adjacent areas, it only extends peripherally into the Northern Cape