Description :

• Annual or perennial herbs or undershrubs, glabrous to densely hairy
• Leaves usually opposite, entire or toothed, petiolate
• Flowers regular or slightly irregular, sessile, usually situated in depressions on thickened rachis of an elongated spike; bracts lanceolate, rigid, persistent
• Calyx persistent, closely adpressed, not accrescent, subequally 5-toothed, 5-ribbed
• Corolla purple, hypocrateriform, with 5 equal or unequal lobes, sometimes hairy in throat
• Stamens 2, arising on and included in corolla tube, with 2 or 3 staminodes; filaments slightly longer than anthers; anthers with diverging thecae
• Ovary entire, 2-locular; style ± as long as corolla tube, terete, with capitate stigma
• Fruit dry, included in calyx, cylindric, separating into 2 1-seeded, truncate mericarps
• Seeds linear, without albumen
• x = 8 (polyploidy)

Nomenclature:

• *Stachytarpheta Vahl
  • Vahl: 205 (1804)
  • Phillips: 637 (1951)
  • Moldenke & Moldenke: 246 (1983)
  • Verdcourt: 17 (1992)

Distribution & Notes:

• Global : Species 65, in tropical and warm regions of America, tropical areas of the Old World (few)
• Southern Africa : Species 2: * Stachytarpheta mutabilis (Jacq.) Vahl and * S. urticifolia (Salisb.) Sims are naturalised in Mpumalanga and KwaZulu-Natal