A patient made a self-diagnosis of athlete's foot (Tinea pedis) and began using a product adveised on television. The condition improved but did not clear and then the patient showed himself to a Dermatologist. A skin scraping was sent to the laboratory for culture, including culture for fungi. The fungal culture yielded a slow growing colony, which produces abundant microconidia . This is consistent with isolation of a dermatophyte of the genera -