Systematic study of Digitaria section Digitaria (Poaceae) in southern Africa

The section Digitaria Veldk. to which Digitaria sanguinalis (L.) Scop. belongs, is represented in southern Africa by five species. Two species namely D. acuminatissima Stapf and D. nuda Schumach., were not previously recorded from southern Africa. Characters traditionally employed to differentiate between species in this taxonomically difficult section were found to be useful to distinguish between the southern African species. These characters include the relative length of the upper glume and lower lemma, the absence of the lower glume, spiculate lateral veins of the lower lemma, arrangement of racemes, length of the ligule and pubescence of the lamina. The presence of secondary racemes and setae on the racemes was found to be variable in some of the species and the suggestion by some authors that they may be of diagnostic value cannot be justified