Abstract
Cosmarium knopkirri Levanets & Janse van Vuuren sp. nov. (Desmidiaceae, Zygnematophyceae) is a newly discovered desmid species collected from an inland wetland system near Palma, Cabo Delgado Province, northern Mozambique. The diagnostic features distinguishing it from other species in the genus include semicells decorated with four concentric, alternating rows consisting of well-developed, large granules. Granules of one row alternate approximately half of the inter-granule distance with respect to those in the next row. The apical circle consists of 6 finger-like granules, while 6, 8 and 10 hemispherical granules are present on the circles located subapical, median and adjacent to the sinus, respectively.