4. Pleurotaenium subcoronulatum f. majus M.F. Rich 1935: 128, no fig. (as “ major ”)

Type locality: Zimbabwe, large pool or “pan” at Old N’gamo [now Gamu, Matabeleland North Province], over an acre in extent, the water in the deeper portions was more than waist-deep and contained a dense tangle of aquatic and semiaquatic vegetation (floating filamentous algae and plankton, as well as epiphytic algae growing on Utricularia and Naias), 3000 feet [914.4 m] a.s.l., pH 7.3m, collected by Miss E. L. Stephens, July 3, 1930.

Description: The semicells of this taxon are much wider than any forms previously described, the width across the basal swelling measuring 55 μm. The cell wall is punctated, and the crown of tubercles correspond to that of the type.

Distribution:

Africa: Zimbabwe (Rich 1935).