UREDINALES OF GUATEMALA 
437 
70. Uromyces Epicampus Diet. & Holw. (on Poaceae). 
Epicampes macroura Benth., San Rafael, 7000 feet alt., Dept. 
Guatemala, Jan. 7, 1915, 11, III, 26. 
Known also from Mexico, but a rather rare species. The aecia 
are as yet unknown. 
71. Uromyces Commelinae (Speg.) Cooke (on Commelinaceae). 
Tradescantia cumanensis Kunth, Guatemala City, Jan. 9, 191 7, 
11, 683 ; San Felipe, Dept. Retalhuleu, Jan. 13, 1917, II, 710. 
This imperfectly known rust rarely produces telia in the warmer 
regions of its range. This is the only record for its occurrence on 
Tradescantia, except the type collection from Argentina. 
72. Uromyces socius Arth. & Holw. sp. nov. (on Loranthaceae) . 
Loranthus crassipes Oliver (?), Solola, 6000 feet alt., Feb. i, 191 5, 
12, III, i6q; San Lucas Tollman, 5100 feet alt., Dept. Solola, 
Feb. 3, 1915, I2, III, 
Loranthus sp., Antigua, Dept. Sacatepequez, March i, 1916, II, 
III, 5jp; same, March 2, 1916, I2, III, S4S (type); Panajachel, 
Dept. Solola, Jan. 3, 1917, III, 66^. 
Struthanthus densiflorus (Benth.) Mart., Huehuetenango, Jan. 22, 
1917, ii. III, 765. 
Aecia chiefly hypophyllous, crowded upon distended bladder- 
like areas 0.3-2 cm. across, short cylindric, 0.4-0.8 mm. in diameter, 
about 0.4 mm. high; peridium erect, erose; peridial cells rectangular or 
rhombic in side view, 23-26 by 35-45 abutted or slightly over- 
lapping, the outer wall 4-8 /x thick, transversely striate, smooth, the 
inner wall 7-10 At thick, closely verrucose; aeciospores eUipsoid or 
oblong, 23-27 by 26-35 m; wall colorless, 2-3 ji thick, closely and 
finely verrucose. 
Uredinia mostly hypophyllous, crowded in small circinating groups 
1-4 mm. across, soon filled with teliospores, early naked, cinnamon- 
brown, pulverulent, ruptured epidermis evident; urediniospores fusi- 
form or fusiform-ellipsoid, 16-26 by 37-55 m; wall golden-brown, 
1.5-2.5 IX thick, moderately echinulate, the pores distinct, 4, equatorial. 
Telia amphigenous, crowded in small circinating groups 1-4 mm. 
across, ellipsoid or oblong, 0.3-0.8 mm. long, compact, blackish, 
ruptured epidermis conspicuous; teliospores ellipsoid, obovoid or 
oblong-obovoid, 18-24 by 29-35 A^, rounded at both ends or somewhat 
narrowed below; wall dark chestnut-brown, 2-3 ij, thick, thicker above, 
5-9 /z, longitudinally verrucose-rugose in more or less broken lines 
1-3 IX apart; pedicel colorless, as long as the spore, verrucosely rough- 
ened. 
