CLINTON: NORTH AMERICAN USTILAGINEAE. 
341 
more in length ; spores light to dark reddish brown, irregular, 
ovate to subspherical, often pointed, with thin, smooth walls, chiefly 
8-11 /x in length. 
Host: j Bouteloua breviseta , N. Mex. (type). 
Grifliths notes that this smut greatly modifies the leaf sheaths, 
internodes, and branching of infected plants so that they resemble 
miniature witches’ brooms. The smut was found very abundantly 
near Roswell, N. Mex. It is distinguished in the field from the 
other two smuts occurring on Bouteloua leaves by the effect on 
the host and by the absence of any pustular sori. 
Ustilago Mexicana Ell. & Ev. 
Ustilago Mexicana Ell. & Ev., Journ. Myc., 3: 56. 1887. 
Exsiccati : Ustilago Mexicana Ell. & Ev., on Miihlenbergia sp., Ell. & 
Ev., N. A. Fungi, 1891. 
Sori in the individual spikelets usually infecting all, ovate, small, 
about 1 mm. in length, more or less concealed by the enveloping 
glumes ; spores reddish brown, often lighter colored on one side 
due in part to the thinner wall, ovoid to spherical or somewhat 
angular and irregular, smooth, 5.5-8 /x in length. 
Host: Mulilenbergia sp., Mex. (type). 
The spores of this species are very similar to those of Ustilago 
Ilordei though the general appearance of the infected inflorescence 
is quite different. The germination has not been reported. 
Ustilago Hordei (Pers.) Kell. & Sw. 
Reticularia segetum Bull., Hist. Champ., pi. 472. 1791. p. p. 
Uredo segetum a Hordei Pers., Disp. Meth. Fung., 57. 1797. 
Uredo carbo DC., Fl. Fr., 6 : 76. 1815. p. p. 
Ustilago segetum Ditm., Sturm’s Deutsch. FL, in, 1 : 67. 1817. p. p. 
Caeoma segetum Lk., Sp. PL, 6 2 : 1. 1825. p. p. 
Erysibe vera a Hordei Wallr., Fl. Crypt. Germ., 2 : 217. 1833. p. p. 
Uredo Carbo-Hordei Philipp , Traite Carie Cliarb , 92. 1837. p. p. 
Ustilago Carbo a vulgaris c Ilordeacea Tul., Ann. Sci. Nat., Bot., in, 7 : 
80. 1847. p. p. 
Ustilago segetum var. Hordei f. tecta Jens., Om Korns. Branch, 61. 1888. 
Ustilago hordei var. tecta Jens., Le Cliarb. Cer6ales, 4. 1889. 
Ustilago Hordei Kell. & Sw., Ann. Rep. Ivans. Agr. Exp. Sta., 2 : 268. 
1890. 
