594 



FUNGI IMPERFECTi: THE IMPERFECT FUNGI 



whole mycelium become transformed into chains of individual spherical, 

 dark-colored conidia. Some of the species form the mildews that are 

 destructive to cloth, paper, etc. Periconia with its head of dark rounded 

 or oval spores at the top of a tall conidiophore reminds one of the Moni- 

 liaceous genera centered around Oedocephalum. Other dark, round-spored 

 genera are Hadrotrichum and Nigrospora. (Fig. 200A.) In both of these the 

 conidiophore is of moderate length and dark-colored. In the former the 

 conidium narrows at the point of attachment. In Nigrospora there is a 

 sort of vesicle, rather light in color, at the apex of the conidiophore, and 

 on this lies the very dark-colored spore. Apparently some of the species 

 are parasitic, mainly upon Monocotyledoneae. N. oryzae (B. & Br.) Fetch 

 {Basisporium gallarum Moll.) causes injury to the nodes of the stalks and 

 to the ears and especially to the pointed bases of the grains of Zea mays L. 

 The genus Zygosporium is peculiar in the manner of bearing the hyaline or 

 almost hyaline, spherical conidia. These are produced singly at the tips of 

 two or three hyaline phialides produced near the apex, on the convex 

 surface of a peculiar dark-colored, curved, and often pointed structure 

 called by Mason (1941) a falx. This was interpreted by Giesenhagen 

 (1892) as a basidium and the fungus placed under the name Urohasidium 

 in the Exobasidiaceae, but Mason's studies show that this interpretation 

 was erroneous. (Fig. 200B-C.) 



Fig. 200. Moniliales. Some peculiar fungi. Family Dematiaceae. (A) Nigrospora 

 panici Zimmermann {Basisporium of some authors). (B) Zygosporium echiiiosporum 

 Bunting & Mason, showing the characteristic falces each bearing three phiahdes with 

 spores. (C) Zygosporium oscheoides Mont, with two phialides on each falx. (D) Lateral 

 view of a falx showing one phialide with spore. (A, after Zimmermann: Cenir. Bakt. 

 Parasitenk., Zweite Abt., 8(7):216-221. B-D, courtesy, Mason: Annotated account of 

 fungi received at the Imperial Mycological Institute, List II, Fascicle 3 (Special 

 Part), pp. 134-144.) 



