Observations on Gymnoascaceae. V. Developmental Morphology of Two Species Representing a New Genus of the Gymnoascaceae

Abstract

A new genus, PSEUDOARACHNIOTUS is described to include 2 spp., P. roseus and P. citrinus (Arachniotus c. Massee and Salmon). The develop-mental morphology and other diagnostic characteristics for these 2 spp. are presented. In both spp., the gametangia consist of distinct antheridia and ascogonia. Ascogenous hyphae produce asci through the intervention of croziers. In each sp. the asci are lacking peridial hyphae, therefore, discrete cleistothecia are absent. This characteristic lack of a peridium, in addition to the presence of antheridia and ascogonia, the formation of croziers, and the lack of conidia on phialides, distinguish the new genus, Pseudoarachniotus. The characteristics of Arachniotus candidus as compiled from the literature and from observations on a non-fruiting strain, are presented. The validity of the genus Arachniotus is discussed, along with the interrelationships among Byssochlamys, Talaromyces, Pseudoarachniotus and Arachniotus.