304 BOTANICAL GAZETTE [APRIL 
by another species, P. notha- (18), from which it is, however, readily distin- 
guished by well marked characters. In P. notha the uredinia are not accom- 
panied by paraphyses and the spores are colorless. The teliospores, while 
similar to the present species in shape and size, have verrucose markings and 
long pedicels. In P. rata the sori are in general hypophyllous, while in P. notha 
they are characteristically epiphyllous on the specimens examined. 
17. Puccinia idonea Jackson and Holway, sp. nov. 
O and I. Pycnia and aecia unknown. 
II. Uredinia amphigenous, scattered or somewhat crowded and 
frequently confluent along the midribs and larger veins, roundish 
or somewhat elongated, o.3-o0.6 mm. across, early naked, pulveru- 
lent, lemon yellow fading to white, ruptured epidermis conspicuous; 
urediniospores broadly ellipsoid or obovoid, 18-21 by 23-28 u, wall 
colorless, thin, 1-1.5 yu, finely and moderately echinulate, the pores 
obscure but apparently equatorial. : 
III. Telia amphigenous, chiefly hypophyllous, scattered or 
somewhat crowded and frequently confluent along the midribs and 
larger veins, roundish or somewhat elongated o.3—0.6 mm. across, 
early naked, pulvinate becoming pulverulent, blackish brown, 
ruptured epidermis conspicuous; teliospores broadly ellipsoid, 
23-28 by 35-45 m, rounded at both ends, not or scarcely constricted, 
wall chestnut brown, medium thick 3~4 u, slightly thickened at 
apex and over pore of lower cell to 7 4, prominently and evenly 
verrucose with broad low projections rather closely set, sometimes 
arranged in lines; pedicel colorless, flexuous, twice the length of 
the spore, 3-5 thick, transversely rugose at base and swelling 
slightly. 
On Vernonia triflosculosa H.B.K., San Jose, Costa Rica, January 8, 1916, 
Holway 398; January 18, 1916, Holway 445; Chinaulta, Dept. Guatemala, 
February 12, 1916, II, III, Holway 481; Esquintla, Guatemala, February 17; 
1916, II, III, Holway 498, 499, type; Panajachel, Dept. Solola, Guatemala, 
January 3, 1917, II, U1, Holway 670. 
This species occurs on the same host and from the same region as P. praealta 
(cf. 20), but differs in the character of the sori as well as in microscopic charac- 
ters. It is perhaps most closely related to the next described species. The 
urediniospores, however, are narrower and shorter, with little or no tendency 
to be globoid. The teliospores in this species, while similar in size and shape, 
have markings which are less pointed and hence nearly hemispherical and 
somewhat more closely placed. The pedicel has a tendency to swell slightly 
