Onychocola canadensis
Onychocola canadensis is an uncommon cause of distal and lateral subungual or white superficial onychomycosis.
However, it may sometimes be present in an abnormal-appearing nail as an insignificant finding, not acting as a pathogen.

Culture of Onychocola canadensis.
RG-2 organism.
Morphologial description:
Colonies grow slowly and are velvety to lanose, white to yellowish, with a brownish reverse. Arthroconidia are cylindrical to broadly ellipsoidal, one to two-celled, hyaline to subhyaline, 4-16 x 2-5 µm in size, forming long chains. Older cultures may show broad, brown, rough-walled hyphae.

Arthroconidia of Onychocola canadensis.
Key features:
Slow growing, white, arthroconidial mould isolated from nails.
References:
Sigler and Congly (1990), Sigler et al. (1994), Gupta et al. (1998), de Hoog et al. (2000, 2015).