Compilation
Marsilea fischeri

This is the plant which Dinter distributed widely under the manuscript name M. pubescens. It is closely related to both M. macrocarpa and M. unicornis Launert but clearly distinguished from these species by its peculiar indument which consists of a mixture of two different types of hair. The laterally attached hairs are peculiar to the genus Marsilea and besides minor variations fairly uniform throughout. M. farinosa is the only species in which ordinary uniseriate hairs could be found. In dried specimens their cells are usually collapsed and thus the hair is coiled or bent. In this state the entire plant appears greyish-farinose. In shape the sporocarps are almost identical to those of M. unicornis. In the latter species, however, the superior tooth is generally much more prominent and always acute. The assumption that M. farinosa is a segregate of M. macrocarpa is strengthened by the disjunct area of distribution. As is the case in M. macrocarpa the East African specimens are slightly larger and lozenge-shaped rather than bean-shaped; the angle between its longitudinal axis and the pedicel is usually much larger than in the South African specimens. M. farinosa seems to be semi-aquatic or terrestrial. I have not seen any specimen with floating leaves.J.E. Burrows (Bothalia 19: 169 (1989)) divided this species into two subspecies. Subsp. arrecta occurs only in NW Transvaal and S Botswana.