CLINTON: NORTH AMERICAN USTILAGINEAE. 
447 
and usually one to several interior fertile cells , of small to medium 
size ; spores generally dark colored, variable, of medium size ; germ¬ 
ination by a short promycelium producing terminally grouped spor- 
idia which give rise to similar secondary sporidia or to infection 
threads. 
The sori of this genus often have resemblance to those of Usti¬ 
lago. Sometimes considerable distortion is produced in the infected 
parts. In some species the cortex but partially covers the spores 
and there is a tendency for the balls to separate into their elements. 
Polysaccopsis is similar to Urocystis as to spore balls, but differs 
in the nature of the sorus. Papulospora is a Hyphomycete having 
spore balls also very similar in appearance. Saccardo describes 
34 species; 12 have been found in North America. 
Urocystis Waldsteiniae Pk. 
TJrocystis Waldsteiniae Pk., Ann. Rep. N. Y. St. Mus., 46: 32. 1893. 
Ustilago Waldsteiniae Paz., Rab.-Wint.-Paz., Fungi Eur., 4011. 1895. 
Urocystis gei Ell. & Ev., Bull. Torr. Bot. Club, 27 : 572. 1900. 
Exsiccati : Urocystis Gei Ell. & Ev., on Geum ciliatum, Ell. & Ev., Fungi 
Col., 1595; Urocystis Waldsteiniae Pk., on Waldsteinia fragarioides, 
Shear, N. Y. Fungi, 86, Ell. & Ev., N. A. Fungi, 2983, Ell. & Ev., Fungi 
Col., 137, Syd., Ust., 248, Seym. & Earle, Econ. Fungi Clinton Ust. Supp., 
C 62; Ustilago Waldsteiniae (Pk.), on Waldsteinia fragarioides, Rab.- 
Wint.-Paz., Fungi Eur., 4011. 
Sori on leaves, epiphyllous, oval to linear, forming pustules that 
follow the veins and are covered at first by a false indusium that 
dehisces through the center and spreads back on either side disclos¬ 
ing the olive black dusty spore mass; spores simple or often adher¬ 
ing rather temporarily together in pairs or groups of 3 or 4, reddish 
brown, rather irregular, oblong to polyhedral or often subspherical, 
smooth, 9-14 /a, occasionally 16 /x, in length. 
Hosts: Geum ciliatum , Wash, (type U. gei)’, Waldsteinia 
fragarioides , N. Y. (type), Wise. 
This fungus is peculiar in that while it has the general aspect of 
an Urocystis its position under this genus is somewhat doubtful 
since it lacks the peripheral layer of sterile cells. Neither does it 
seem to be a true Ustilago, as considered by Pazsclike, since the 
spores adhere somewhat in pairs or small groups. The species needs 
further study, especially of the formation and germination of its 
