Description of two rare Gerronema species growing on Marchantia thalii is presented. The main distinguishing features of both species, their ecology, and distribution, are described. G. postii is associated with fireplace mosses. G. marchantiae, an alpine element, has been recorded in Czechoslovakia for the first time.
Klán J. (1992): Two Gerronema species growing on Marchantia thalli 1. G. marchantiae Sing. et Clém., 2. G. postii (Fr.) Sing. – Česká Mykologie 46(1-2): 121–125.
