SILIKATAUSWÜCHSE AN DEN INNEREN STIGMENÖFFNUNGEN BEI GOMPHONEMA-ARTEN

Abstract

Stigmata are common features in the genusGomphonema and many species have one or several of them. But in contrast to many other genera, e.g. Cymbella, they are very simple constructions. In general they consist of a porus with a roundish external and a roundish to slit-like internal opening. More complex structures are known in few species only. This paper gives a description and discussion of the different types of siliceous outgrowths at the internal opening of stigmata in the genus Gomphonema. Three species with corresponding structures are described as new, two from Europe (G. angustius, G. supertergestinum) and one from Cuba (G. insignaffine). In addition, more precise data on some established taxa are given.