Description :

• Annual or perennial herbs, rarely shrubs, polygamous
• Leaves narrowly linear to lanceolate to elliptic to ovate to rhomboid, often deeply divided, lobes even further divided; apex acute, sometimes ending in a stiff point; sagittate, cuneate or rounded at base, narrowing to a short petiole; glabrous, hirsute, tomentose, strigose, glandular-punctate on one or both surfaces, or covered with cup-shaped or elongated scales; ocrea stem-clasping, membranous, truncate, fringed with terminal rigid setae or without, or deeply lobed, sometimes with a green leaf-like limb
• Inflorescence a solitary, terminal or axillary thyrse with fascicles of up to 4 flowers in axils of brown, cup-shaped bracts
• Flowers bisexual or unisexual, heterostylous
• Perianth 5-lobed and long-persistent in bisexual flowers; outer segments keeled at apex; tube constricted above ovary, glabrous or densely white-pilose
• Stamens 8, arising on inner perianth; filaments with a ring of brown cilia ± an eighth from base; anthers usually bluish
• Ovary 3-angled; styles 3, connate at base; stigmas capitate
• Fruit a 3-angled nut, sometimes winged, or armed with small rudimentary teeth at base, sometimes longitudinally ridged, warted between ridges
• x = 13 (1 report, polyploidy)

Nomenclature:

• Oxygonum Burch. ex Campd.
  • Campderá: 18 (1819)
  • Wright: 459 (1912)
  • Graham: 145 (1957)
  • Graham: 6 (1958)
  • Brandbyge: 541 (1993)

Distribution & Notes:

• Global : Species ± 32, mostly confined to Africa, except for two species, one of which is an endemic on Madagascar
• Southern Africa : Species 6, widespread but absent in Western Cape