Nitzschia epiphytica versus Nitzschia epiphyticoides, and Nitzschia pseudepiphytica (Bacillariophyta), three small Nitzschia from East and Central Africa.

Nitzschia epiphytica and N. epiphyticoides are two small diatoms from Central and East Africa described by Müller in 1905 and by Hustedt in 1949, respectively. To reduce the confusion that exists between the two species, the type of N. epiphyticoides and the original material of N. epiphytica were reexamined by light and scanning electron microscopy. Because N. epiphytica was described from several samples by Müller, a lectotype is designated. The variability of these two Nitzschia species was studied using both historic material and more recent material from Lake Tanganyika. A third taxon, Nitzschia pseudepiphytica, which corresponds rather well with the emended species description of N. epiphytica given by Hustedt in 1949, is described. The distribution of these three small Nitzschia species is probably restricted to tropical Africa and reported occurrences elsewhere in the world need to be re-investigated. KEY WORDS: Africa, Diatoms, Nitzschia, Taxonom