A PARASITIC SPECIES OF CLAUDOPUS 
Harry Morton Fitzpatrick 
(With Plate 153, and i Text Figure) 
Several of the Agaricaceae have been described as parasitic on 
others of the same group. Of these may be mentioned V olvaria 
Loveiana on Clitocybe nchularis,'^ Stropharia coprhwphiia on 
Coprinns atramentarius,- and the species of the genus Nyctalis. No 
instance of a species of the Agaricaceae parasitic on one of the 
Polyporaceae appears, however, to have been cited. On August 
2, 1914, the writer discovered such a case in Six Mile Gorge, near 
Ithaca, N. Y. Polyporus perennis^ occurs in this locality in un- 
usual abundance and a few fruit bodies of this fungus were found 
parasitized a member of the genus Claud opus. Study has proved 
this to be a hitherto undescribed species. 
The fruit bodies of the parasite occur in considerable numbers 
about the mouths of the tubes and along the stipe of the Poly- 
porus. They are minute, the expanded pilei in no case exceed- 
ing 4 mm. in diameter, while the developmental stages or “ but- 
tons ” are almost microscopic. The lateral stipe and the salmon- 
colored gills suggest at once the genus Claudopus. 
The parasitized host plants, if examined superficially, give 
little evidence of the presence of the parasite. They exhibit the 
normal appearance of healthy plants, showing neither hyper- 
trophy nor dwarfing, and viewed from above can in no way be 
distinguished from the uninfected sporophores. An examination 
with the hand lens reveals the fact that certain of the tubes of the 
Polyporus in the immediate vicinity of the fruit bodies of the 
parasite are partially filled with the grayish mycelium of the 
Claudopus. There is no other external evidence of a diseased 
iBerkeley, J. M. Outlines of British Fungology, pi. 7, f. 2. i860. 
2 Atkinson, G. F. A mushroom parasitic on another mushroom. The Plant 
World 10: 121-130. f. 22-24. 1907- 
■1 Polyporus perennis Fr. = Coltricia perennis (L.) Murrill. North Ameri- 
can Flora 9: 92. 1908. 
34 
