Hypoxylon diatrypeoides Rehm

TELEOMORPH | CULTURES AND ANAMORPH | SPECIMENS EXAMINED | NOTES

NOTES

Hypoxylon diatrypeoides has been found only in Brazil and New Zealand. Stromata are superficial on decorticated portions of the substrate or erumpent on corticated portions. Hypoxylon ferrugineum is similar, but differs in having smaller ascospores, in being confined to the northern hemisphere, and in being constantly associated with Tilia.

A specimen, Usteri no. 121a at S, was mistakenly cited twice by Miller (1961) as the type material of H. diatrypeoides and H. rubrostromaticum [= H. subrutilum], respectively. The confusion probably came from Rehm's hand-writing on the packet of this specimen where he wrote "Thuemenella sacoxyloides Rehm, nov. spec." but crossed it out later. Thereafter, he wrote "Hypoxylon (Clitoxylon) diatrypeoides Rehm, nov. spec." on the top of the same packet, then crossed out the species epithet "diatrypeoides" and replaced it with "rubrostromaticum". Eventually, only the name H. diatrypeoides went into press (Rehm, 1907). This material fits well Rehm's original description of H. diatrypeoides, and is also exactly the fungus in the photograph on Pl. 4, Fig. 10 in Miller (1961). Undoubtedly, Usteri no. 121a is the type of H. diatrypeoides Rehm rather than of H. rubrostromaticum Miller. The other specimen cited in Miller (1961), Rick, J. no. 32a [BRAZIL: Rio Grande do Sul, São Leopoldo, 1.5.1906 (BPI 58858)], is not this fungus. It probably belongs to Nemania. Pande's H. diatrypeoides [AMH 3895] from India (Pande, 1979) is a Diatrype.

It seems noteworthy that the ascus apical ring of New Zealand collections blues in Melzer's reagent, whereas the asci of South American specimens seem to lack an apical ring. It is possible that two taxa are involved here, but we were unable to make a decision because we did not have cultures from collections from either area.