Description:

• Perennial, slender, trailing or scrambling shrubs, hemiparasitic on roots; stems flexible, much branched, somewhat woody
• Leaves opposite, petiolate, ± ovate in outline, dentate to pinnatifid or pinnatisect, coriaceous
• Flowers solitary, axillary, pedicellate, bracteate and bibracteolate
• Bracts small, deciduous; bracteoles opposite, subsessile just below calyx, deciduous
• Calyx tubular, (4)5-lobed, somewhat leathery, inflated in fruit; tube ± campanulate or urceolate, 10-veined; lobes ovate, spreading, shorter than tube
• Corolla tubular, 5-lobed, slightly irregular; tube narrow at base, inflated and ± funnel-shaped above, somewhat curved, with wide throat; limb spreading; lobes rounded, shorter than tube, subequal but posterior pair smallest, interior in bud
• Stamens 4, didynamous, included, glabrous; upper pair arising in lower part of expanded portion of corolla tube; lower pair arising lower down, in upper part of narrow portion of tube; filaments linear; anthers connivent in pairs, bithecate or unithecate by abortion: upper stamens with one theca empty and vermiform, lower stamens with empty theca absent; staminodes 0
• Ovary bilocular, globose, glabrous; ovules many per locule; style filiform, curved above, exserted; stigma obscurely 2-lobed
• Fruit a globose, glabrous, loculicidal capsule, enclosed in enlarged, persistent calyx
• Seeds many, conical-cylindrical, truncate at both ends; testa reticulate

Nomenclature:

• Buttonia McKen ex Benth.
  • Bentham: 63, t. 1080 (1871)
  • Hiern: 384 (1904)
  • Hemsley & Skan: 439 (1906)
  • Hennessy: t. 1815 (1980)
  • Visser: 82, 157, tt. 148-152 (1981)
  • Philcox: 141 (1990)

Distribution & Notes:

• Global: Species 3, tropical and southern Africa
• Southern Africa: Species 2: Buttonia natalensis McKen ex Benth. and B. superba Oberm., Northern Province, Mpumalanga, Swaziland and KwaZulu-Natal