A contribution to the taxonomy of the genus Coniocessia (Xylariales)

Abstract

The ascomycete genus Coniocessia has recently been established to accommodate the only and type species, C. nodulisporioides, with nodulisporium-like anamorph, formerly classified in Coniochaeta. Four new Coniocessia species are described here, three of which were isolated from cereal seeds and straw in Iran and one from goat dung collected in Spain, using morphological and molecular data (sequences of the ITS and D1-D2 regions of the LSU-ribosomal DNA) as well as growth–temperature relationships. Parsimony and neighbor-joining analyses based on the D1-D2 regions of the LSU strongly supported the placement of Coniocessia as a monophyletic clade within the new family Coniocessiaceae and Coniolariella within the Xylariaceae (Xylariales). Coniocessia maxima is differentiated from the closest species, C. nodulisporioides, by larger ascomata and asci, and more richly branched, macronematous conidiophores with very distinct, elongated conidiogenous cells. Coniocessia cruciformis has ascospores with strongly thickened longitudinal rim, appearing rather cruciform in side view; micronematous conidiophores and less distinct conidiogenous cells. Coniocessia minima possesses small ascomata maturing very slowly, with an opaque peridium and inaequilaterally flattened ascospores; conidiogenous cells are bulbose to club-shaped, conidia globose to subglobose. Coniocessia anandra, the only species lacking an anamorph, is mainly characterized by translucent ascomata with a broad ostiole.