Hygrophila didynama (Lindau) Heine

Erect or somewhat scrambling, many-stemmed perennial herb, growing from a creeping rhizome. Stems up to 1.5 m long, 4-angular, hairless or finely velvety, sometimes with scattered stalked glands. Leaves opposite, lanceolate or narrowly elliptic, up to 16 cm long, almost hairless or roughly hairy. Flowers in a large, open, branched inflorescence up to 75 cm long; axes with few to many stalked glands and ovate leaf-like bracts. Corolla pale mauve to purple with conspicuous orange veining, 3-4 cm long, 2-lipped; tube wide, almost saccate. Capsule 20-35 mm long, hairless.

DRC, Sudan, Tanzania, Malawi, Zambia and Zimbabwe