Cladobotryum penicillatum sp. nov. was isolated from Alnus twigs in New Forest, Hampshire, U. K., in 1971, and from Sebacina effusa in the Houtribbos Forest, O.- Flevoland Polder, Netherlands, in 1980. The species has conidia intermediate in dimension between C. varium and C. mycophilum, and it differs from both species by having rather slow-growing colonies and long conidiophores with apical penicillate branching. Conidiogenesis is basipetal and retrogressive.