Potamogeton schweinfurthii A. Benn.

schweinfurthii: named after Dr Georg August Schweinfurth (1836-1925), German botanical collector and taxonomist.

Submerged herb to 2 m from a rhizome. Stipules 2-4 cm, persistent, open, convolute, the lower amplexicaul, the upper spreading, lanceolate. Leaves 10-20 × 1-2 cm, linear-lanceolate, sessile, submerged (occasionally the upper floating), thinly-textured (the floating ones coriaceous); apex apiculate; margin finely undulate, entire. Spikes on swollen scapes, more than 20-flowered. Drupe 3-4 mm, ovoid, smooth; beak short.

Widespread in tropical Africa, South Africa and Madagascar. Also in North Africa, Azores, Mediterranean islands and southwestern Asia.