Potamogeton schweinfurthii

The pondweed Potamogeton schweinfurthii is native to tropical Africa and the Azores.¹ In Lake Malawi and Lake Tanganyika it forms underwater meadows down to about 4 m, preferably in sheltered sandy bays and where rubble gives way to sand; it appears to be absent from the open, surf-exposed shore.¹ The narrowly elliptic to lanceolate, olive-green to brownish-red leaves usually reach up to 16 cm in length and are borne on upright stems up to approx. 3.5 m long that arise from a branched rhizome.¹ In the wild the hard, tough blades are conspicuous, and lime is deposited on them owing to the extreme water chemistry of the lakes.¹

The rarely cultivated species is regarded as undemanding and adaptable, but remains much smaller in the aquarium than in nature.¹ Plants from the two lakes do particularly well in hard, alkaline water.¹ Creeping rhizomes and side shoots make propagation easy.¹