CLINTON: NORTH AMERICAN USTILAGINEAE. 
345 
found on the leaves as well as in the inflorescence. Brefeld, Keller- 
man and Swingle, and others have reported the germination in this 
species. Literature : 5, 7, 17, 18, 19, 20, 22, 27, 30, 67, 77, 84, 86, 
88, 89, 90, 92, 94, 95, 98, 103, 106, 156, 157, 170. 
Ustilago nuda (Jens.) Kell. & Sw. 
Uredo carbo DC., FI. Fr., 6 : 76. 1815. p.p. 
Ustilago segetum Ditm., Sturm’s Deutsch. FI., in, 1: 67. 1817. p.p. 
Caeoma segetum Lk., Sp. PL, 6 2 : 1. 1825. p. p. 
Erysibe vera a Hordei Wallr., FI. Crypt. Germ., 2 : 217. 1833. p. p. 
Uredo Carbo-Hordei Philipp., Trait6 Carie Charb., 92. 1837. p. p. 
Ustilago Carbo a vulgaris c Hordeacea Tul., Ann. Sci. Nat., Bot., in, 7 : 
80. 1847. p. p. 
Ustilago segetum var. Hordiii. nuda Jens., Om Korns. Brand., 61. 1888. 
Ustilago Hordei Bret., Nach. Klub Landw. Berl., 1593. 1888. p.p. 
Ustilago hordei var. nuda Jens., Le Charb. Cereales, 4. 1889. 
Ustilago nuda Kell. & Sw., Ann. Rep. Ivans. Agr. Exp. Sta., 2 • 211. 1890. 
Ustilago Hordei Rostr., Overs. Kong. Danske Vid. Selsk. Forh., 10. 1890. 
Ustilagidium Hordei Herzb., Zopf Beit. Phys. Morph. Org., 5 : 7. 1895. 
Exsiccati: Ustilago nuda (Jens.) Kell. & Sw., on Hordeum sp. cult., 
Seym. & Earle, Econ. Fungi, 82a, Seym. & Earle, Econ. Fungi, Clinton 
Ust. Supp. C 77, C 78. 
Sori in spikelets, forming a dusty olive brown spore mass, about 
6-10 mm. long by half as wide, temporarily protected by thin mem¬ 
brane but soon becoming dissipated and leaving behind naked 
rhachis ; spores lighter colored on one side, minutely echinulate, 
subspherical to spherical or occasionally more elongated, 5-9 p in 
length. 
Hosts : Hordeum sps. cult., Conn., Ia., Ill., Ivans., Mass., Md., 
Mich., Minn., Miss., Mo., N. Car., N. H., N. Y., Ohio, S. Dak., Tex., 
Wise.; Mex.; Nova Scotia. 
There are two species of smuts on cultivated barley but it is only 
during recent years that they have been recognized as distinct. The 
one described above has an olive brown dusty spore mass that is 
soon scattered and the spores are minutely echinulate, while the 
other species, Ustilago Hordei , has a rather permanently aggluti¬ 
nated purple black spore mass and smooth spores. These species 
cause more damage in Europe than in this country because barley is 
more commonly cultivated there. They can be prevented by the 
hot water seed treatment or a modification of it. The germination 
