Taxonomy of Haplosporangium parvum

A strain ofHaplosporangium parvum has been isolated from Italian soil. It has been comparatively studied with six North American and a Korean strain. Two American and the Italian strains are thermophilic (opt. about 35° C) while the other four grow better at temperatures around 20° C. The assimilation of nitrogen sources has been comparatively studied. In addition to peptoneH. parvum metabolizes urea and most aminoacids, whileH. bisporale assimilates peptone, leucine, alanine, glutamic acid and proline only. On the basis of N assimilation and thermophily, a key of the studied strain is established. A comparison ofH. bisporale withH. parvum, confirmed that the former species is a Phycomycete, while the latter is a Moniliaceous, aleuriosporic fungus. All the strains are feebly pathogenic, but the virulence of the Italian soil isolate is equal to that of the most virulent strains isolated from animal lungs (Alberta, Canada). The taxonomy ofH. parvum has been studied in relation to the more or less allied generaAleurisma, Glenosporella, Geomyces andStaphylotrichum. It is concluded thatH. parvum may be better classified as a new genus, and the monotypic genusEmmonsia withE. parva (Emm. etAshb.) n. comb. is proposed, although the entire group of aleuriosporaceous fungi needs revision.