CLINTON: NORTH AMERICAN USTILAGINEAE. 
451 
This smut has very rarely been found in this country though in 
Europe it sometimes causes considerable injury to cultivated violets. 
Prillieux and Brefeld have reported the germination of the spores. 
Literature: 23, 41, 142, 192. 
Urocystis Cepulae Frost. 
Urocystis Cepulae Frost, Ann. Rep. Sec. Mass. St. Bd. Agr., 24 : 175. 1877. 
TJrocystis colchici var. cepulae Cke., Gard. Cliron., 1877 : 635. 1877. 
Exsiccati: Urocystis Cepulae Frost, on Allium cepa, Ell. & Ev., N. A. 
Fungi, 2706, Seym. & Earle, Econ. Fungi Clinton Ust. Supp., C 61. 
Sori in leaves, forming isolated pustules or often affecting them 
for the greater part of their length and breadth, sometimes occur¬ 
ring at their base in the bulbs, upon rupture of covering membrane 
disclosing dusty black brown spore mass ; spore balls ovoid to spher¬ 
ical, small, 17-25 p in length ; sterile cells tinted, ovoid to spherical, 
small, rather completely covering the spores, usually 4-8 /x in length ; 
spores reddish brown, ovoid to spherical, usually 1, rarely 2 in a 
ball, chiefly 12-16 p in length. 
Hosts: Allium Cepa, Conn, (type), Ind., Mass., N. J., N. Y., 
Ohio, Vt.; A. Nevadense , Nev. 
This species causes considerable damage to the onion crop in east¬ 
ern United States. The smut lives in the soil and infects the seed¬ 
lings so that ground that has become infected is a menace to onions 
grown from seed on it even after it has not been planted to onions 
for several years. Such land should not be used or should be used 
for transplanted onions only. There are several methods of treating 
infected land with sulphur, lime, or formalin that have also proved 
of benefit in reducing the amount of smut in the onions raised on it. 
There has been some discussion whether the American species is 
distinct from Urocystis Colchici and Urocystis magica of Europe, 
the latter species also occurring on species of Allium. The three 
while very closely related are distinct. The species described here 
differs from both in having smaller spores and spore balls and also 
from U Colchici by rarely having more than one spore in a ball. 
Thaxter has described the germination. Literature : 35, 37, 53, 158, 
159, 164. 173. 179. 
