Oct. 1902] 
North American Ustilagineae 
13a 
USTILAGO PERENNANS Rostr.— Cintractia avenae Ell. 
& Tr., Joum. Myc. 6:77. My. 1890. 
Host: Arrhenatherum avenaceum, Conn., Ia., Ill., Miss, 
(type Cintractia avenae Ell. & Tr.), Ohio, Verm. 
USTILAGO AVENAE (Pers.) Jens.— Hosts: Avena fatua 
Calif.; A. sativa, commonly distributed over N. Amer. where 
oats are grown. 
USTILAGO NUDA (Jens.) Kell. & Sw. — Host: Hor- 
deum sps. cult., commonly found where barley is raised as a farm 
crop. 
USTILAGO TRITICI (Pers.) Jens. —Host: Triticum 
vulgare, a common parasite on this host in North America. 
USTILAGO MUHLENBERGIAE Clint, n. sp.—Sori in 
the inflorescence, ovoid to subspherical, about 3-6 mm. in length, 
protected by thin, semi-transparent membrane of the infected 
enveloping glumes, upon rupture disclosing black-brown dusty 
spore mass; spores rather dark reddish brown, chiefly spherical, 
with brittle epispore that breaks up into very small granular 
echinulations (especially at opposite sides of the spore thus leav¬ 
ing a darker less broken central band) 4-6 y- in diameter. 
Host: Muhlenbergia texana, Ariz. (type). 
The writer is indebted to Professor Farlow for this species 
which was collected by Pringle in southern Arizona in 1884. It 
is peculiar because of its very small spores and because of the 
curious way, as shawn by an immersion, in which the epi¬ 
spore breaks into granular echinulations. The germination of 
the spores has not been observed. 
USTILAGO RESIDUA Clint, n. sp. — Ustilago segetum 
Auct. p. p. Ustilago segetum f. Danthoniae Ell. and Ev. N. A. 
F. 1893a. 1887. 
Sori prominent, in the inflorescence, infecting the whole, or 
sometimes confined to the individual spikelets, usually enclosed 
by leaf sheaths, on exposure showing as olive brown dusty spore 
mass; spores rather light olive brown, ovoid or ovate to spheri¬ 
cal or occasionally irregular, thin walled, with coarse granules 
giving granular reticulate appearance, usually 5-5-8.5 a> some¬ 
times even iifx in length. 
Hosts: Danthonia compressa N. Y.; D. spicata, N. H.; 
Danthonia sp., Colo. 
This is near Ustilago tritici but has spores more granular 
reticulate, averaging larger and not lighter colored on one side. 
It is one of the forms that have been included in the old species 
Ustilago segetum, and, so far as the writer can ascertain, has 
not, as yet, been given specific distinction. Ustilago danthoniae 
Kalchb., if described accurately, differs decidedly in its much 
larger spores. 
