SANBI Flora Keys Logo
Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.

Apiaceae - Apioideae - Sium L.

Description:

  • Robust herbs in wet places, glabrous
  • Leaves elongate, once-pinnate, with pinnae appearing finely and regularly serrate on margins, teeth curved inwards and often slightly overlapping
  • Flowers in compound, bracteate umbels; involucres and involucels conspicuous
  • Calyx with 5 small or obsolete teeth
  • Petals obcordate, with inflexed apex, white
  • Styles with depressed or slightly conical base, spreading or recurved above
  • Fruit laterally flattened or contracted, subdidymous; mericarps with 5 ridges; oil ducts 6, 4 in furrows, 2 on face; carpophore bipartite
  • Seeds subterete
  • x = 6 (8, 9, 10, 11, 13) (polyploidy)

Nomenclature:

  • Sium L.
    • Linnaeus: 251 (1753)
    • Sonder: 539 (1862) in part, S. thunbergii transferred to Berula
    • Cannon: 598 (1978)
    • Burtt: 247 (1991)
    • Pimenov & Leonov: 105 (1993)

Distribution & Notes:

  • Global: Species 14, ± cosmopolitan
  • Southern Africa: Species 1: Sium repandum Welw. ex Hiern, widespread in the northern and eastern parts and southwards to the Eastern Cape; readily confused with Berula

References: