Studies in Mycology No. 3

Species concept and nomenclature of Phoma and Ascochyta species described by Wollenweber & Hochapfel (1936) are reconsidered by means of a comparative study of literature data, original material and numerous fresh isolates. Their sixteen species have been reduced to thirteen: Phoma betae, P. cava, P. destructiva, P. exigua, P. fimeti, P. glomerata, P. lyopersici, P. macrostoma, P. pomorum, P. putaminum, Ascochyta fabae, A. pisi and Stagonospora samarorum. The synonymy, differentiating diagnostic criteria and host relations of these species are discussed, tabulated and illustrated. Asteromella bellunensis (Mart.), Myxofusicoccum pyrinum (Fr.) and Stagonospora populi (Delacr.) are proposed as new combinations.