430 NORTH AMERICAN FLORA [VOLUME 7 
chestnut-brown, ruptured epidermis noticeable; urediniospores strongly flattened laterally, 
globoid or obovate, 26-32 by 30-34 » when seen in face view, oblong, 18-22 by 30-34 » when 
pores are in optical section; wall dark cinnamon-brown, thick, 2.5~3.5 4, moderately and very 
finely echinulate, the pores 2, opposite, equatorial. 
Il. Telia amphigenous, scattered, round, 0.2-0.8 mmm. across, soon naked, pulvinate 
becoming somewhat pulverulent, dark chestnut-brown, ruptured epidermis conspicuous; 
teliospores ellipsoid or obovate-oblong, somewhat irregular, 20-24 by 32-36 pu, rotmd or obtuse 
at both ends, slightly or not constricted at septum; wall light chestnut-brown, moderately 
thick, 2-2.5 », thickened at apex to 5 by a lighter colored abrupt umbo over pore of upper 
cell which is often placed at one side, the pore of lower cell at septum; pedicel in large part 
deciduous. 
On CARDUACEAE: 
Helianthella californica A. Gray (H. nevadensis Greene), California. 
Helianthella quinquenervis (Hook.) A. Gray, Colorado, Utah. 
Helianthella uniflora (Nutt.) T. & G., Utah. 
Helianthella sp., Wyoming. 
TYPE Locality: Soda Springs, Nevada County, California, on Helianthella californica. 
Disrrisurion: Eastern California to central Wyoming. 
Exsiccatt: Garrett, Fungi Utah. 55, 56, 232. 
251. Dicaeoma Zexmeniae (Dietel & Holway) Arth. Résult. 
Sci. Congr. Bot. Vienne 344. 1906. 
Puccinia Zexmeniae Dietel & Holway; Holway, Bot. Gaz. 24:26. 1897, 
Puccinia opaca Dietel & Holway; Holway, Bot. Gaz. 24:26. 1897. 
Dicaeoma opacum Arth. Résult. Sci. Congr. Bot. Vienne 344. 1906. 
O. Pycnia amphigenous, chiefly epiphyllous, few in crowded groups among the aecia, 
punctiform, inconspicuous, immersed, globoid or pyriform, 65-90 by 90-150 4; ostiolar fila- 
ments becoming agglutinate, 50-100 uw long. 
I. Aecia amphigenous, chiefly epiphyllous, small, usually crowded in small groups 0.1- 
0.2 mm. across or scattered along the veins of the leaf; peridium cylindric, membranous, 0.5-1 
mm. high, erect, becoming deeply and coarsely lacerate and finally erose; peridial cells seen in 
face view oblong or polygonal, 16-20 by 28-34 n, finely verrucose-rugose, somewhat over- 
lapping, the outer wall very thin, less than 1 », the inner wall 3-4 » thick, verrucose; aecio- 
spores globoid or oblong-globoid, 15-20. by 18-24; wall nearly or quite colorless, thin, 
1.5-2 , closely and strongly verrucose. 
II, Uredinia amphigenous, scattered, small, 0.3-0.5 mm. across, round, early naked, 
cinnamon-brown, pulverulent, ruptured epidermis inconspicuous; urediniospores broadly 
ellipsoid, globoid, or obovoid, 14-20 by 18-26 uw; wall light cinnamon-brown, thin, 1.5-2.5 p, 
finely and sharply echinulate, the pores 2, rarely 3, equatorial. 
III. Telia amphigenous, scattered, small, 0.2-0.5 mm. across, round, early naked, be- 
coming somewhat pulverulent, blackish-brown, ruptured epidermis inconspicuous; teliospores 
broadly ellipsoid, often nearly globoid, 24-30 by 30-42 u, rounded at both ends, slightly or not 
constricted at septum, thickened at apex, 4-8 u; of two sorts, germinating form with walls 
cinnamon-brown, 1.5—-2.5 uw thick, resting form with walls chestnut- or chocolate-brown, often 
nearly opaque, 3-5 » thick, prominently verrucose-rugose or reticulate, appearing verrucose; 
pedicel colorless, largely deciduous or once to twice length of spore, sometimes inserted at one 
side. 
On CARDUACEAE: 
Zexmenia aurea Benth. & Hook., Mexico (state). 
Zexmenia ceanothifolia Schultz-Bip., Jalisco, Michoacan, Morelos. 
Zexmenia costaricensis Benth., Guatemala. 
Zexmenia crocea A. Gray, Morelos. 
Zexmenia elegans Schultz-Bip., Michoacan. 
Zexmenia fasciculata Hemsl., Michoacan, Morelos. 
Zexmenia helianthoides A. Gray, Guerrero, Morelos. 
Zexmenia podocephala A. Gray, Jalisco, Michoacan. 
TPH LOCALITY: Guadalajara, Jalisco, on Zexmenia podocephala. 
DISTRIBUTION: Southern Mexico and Guatemala. 
Exsiccati: Barth. N. Am. Ured. 280, 1263; Sydow, Ured. 1823. 
