Description:

• Erect or spreading perennial herbs or undershrubs, often viscid
• Leaves pinnately 3-foliolate; leaflets conspicuously paler-veined
• Flowers yellow, in dense, axillary or terminal heads, each in axil of a leafy bract, or flowers solitary, 2- or 3-bracteolate, or 2 together, one aborting, mainly unisexual, fertile ones often apetalous
• Calyx with slender tube, 5-lobed; lobes membranous, 4 upper connate, lowest slender
• Petals arising in throat of calyx tube; vexillum rounded or obovate, emarginate, sessile; wings shortly clawed; keel incurved, subrostrate
• Stamens monadelphous, arising at mouth of calyx tube; anthers unequal, 5 longer and subbasifixed, 5 shorter and versatile
• Ovary linear, subsessile, 2- or 3-ovuled; style filiform, articulating towards base; stigma small, terminal
• Pod oblong, compressed, beaked, with hooked style-base, segmented
• Seeds ovoid or irregularly oblong, compressed
• x = 10 (polyploidy)

Nomenclature:

• Stylosanthes Sw.
  • Swartz: 108 (1788)
  • Harvey: 227 (1862)
  • Torre: 213 (1966)
  • Verdcourt: 492 (1973)

Distribution & Notes:

• Global: Species ± 25, in the tropics and subtropics of both hemispheres
• Southern Africa: Species 1: Stylosanthes fruticosa (Retz.) Alston (= S. mucronata Willd.), Namibia, Botswana, the four northern provinces, Swaziland and KwaZulu-Natal