Duosperma quadrangulare (Klotzsch) Brummitt

quadrangulare: 4-angled, referring to the stems.

Erect or rarely decumbent, shrubby perennial herb, up to c. 1.2m tall. Stem 4-angled, aromatic when crushed, more or less densely covered with sticky glands and non-glandular hairs. Leaves opposite, elliptic to somewhat obovate, 3 - 20 cm long, hairless or with scattered glossy hairs on the veins; base decurrent; margin almost entire to toothed. Leaves often immature when flowering. Flowers in 1-3-flowered clusters in the upper axils, together often forming racemes or panicles with leaf-like bracts near the base of the inflorescence. Calyx with glandular and non-glandular hairs. Corolla white to mauve-purple with darker markings on the lower lip and a yellow to orange palate with stiff hairs on it. Fruit an obovoid capsule, 7-11 mm long, hairless or with scattered glands near the apex.

Angola, Botswana, DRC, Namibia, Tanzania, Malawi, Mozambique, Zambia, Zimbabwe