Hypoxylon investiens (Schwein.) M. A. Curtis

TELEOMORPH | CULTURES AND ANAMORPH | SPECIMENS EXAMINED | NOTES

NOTES

After examining some specimens determined by the late J. H. Miller, we found that his concept of H. investiens includes H. monticulosum, H. investiens, and H. submonticulosum. He identified some specimens of H. investiens as H. rubiginosum var. dieckmannii [º H. dieckmannii]. The problem probably originated from the type of H. investiens. This material is old, but still possesses several recognizable characteristics: ostioles slightly higher than the stromatal surface, greenish KOH-extractable stromatal pigments, nearly equilateral ascospores, indehiscent perispore, and faint germ slit usually less than spore-length. Miller (1961) weighted ostiolar characters heavily, differentiating his section Hypoxylon from section Papillata solely on ostioles. Nonetheless, a few Hypoxylon taxa, including H. investiens, have variable ostiolar characters. In some material of H. investiens, the stromatal tissue above the ostioles is perforated to give an umbilicate appearance; however, in old material, the stromatal tissue above the ostioles, instead of being perforated, becomes sealed to give a papillate appearance. Hypoxylon monticulosum and H. submonticulosum differ from H. investiens in lacking KOH-extractable pigments, in having a blackish surface on mature stromata, and in having Virgariella-like conidiogenous structures. Hypoxylon dieckmannii and H. investiens differ in the former having dilute pigments or no pigments extracted with 10% KOH solution, and in having a Sporothrix-like conidiogenous structure.

Both Berkeley (1876) and Miller (1961) cited Ravenel's specimen from South Carolina bearing no. 2258 as the type of H. concurrens. A Ravenel specimen, which does not have any number on it, was sent by K on a request for the type of H. concurrens. This specimen may represent a duplicate of the original collection.