Description:

• Erect or spreading, perennial herbs or undershrubs, often woody at base, often densely pubescent
• Leaves opposite or subopposite, mostly ovate or oblong, usually toothed or incised-dentate, petiolate
• Flowers irregular, sessile or shortly pedicellate, in terminal spikes or simple, spicate racemes; rachis not excavated; bracts small and narrow; bracteoles minute or 0
• Calyx obliquely truncate or 5-toothed; tube narrow, 5-ribbed, usually becoming ± dilated below as fruit ripens, at length splitting longitudinally in front
• Corolla infundibuliform or hypocrateriform, white, or dull yellow; tube slender, straight or curved, often widened at apex, glabrous outside, pilose inside between stamens; limb ± oblique, with 5 subequal or unequal lobes, ± 2-lipped
• Stamens 4, didynamous, arising in upper part of corolla tube, included; filaments longer than anthers; anthers with parallel thecae
• Ovary 2-locular, cylindrical or narrowly oblong, glabrous; style nearly as long as corolla tube, linear with heel-shaped bend above; stigma capitate or spatulate
• Fruit dry, straw-coloured to black, oblong, of 2 1-seeded linear-oblong nutlets ribbed on outer face, sometimes winged at apex, minutely verruculose-asperulous on seed-part inside
• Seeds linear, without albumen

Nomenclature:

• Chascanum E.Mey.
  • Meyer: 275 (1838) name conserved
  • Moldenke: 113 (1938)
  • Phillips: 637 (1951)
  • Verdcourt: 11 (1992)
• Bouchea Cham.
  • Chamisso: 252 (1832)
  • Pearson: 197 (1901)
• Plexipus Raf.
  • Rafinesque: 104 (1837)
• Chascanum E.Mey. sect. Pterygocarpum Walp.
  • Walpers: 39 (1845)
• Svensonia Moldenke
  • Moldenke: 129 (1936)

Distribution & Notes:

• Global: Species 30, Africa, Madagascar, Arabian Peninsula to West India
• Southern Africa: Species 14, widespread