166 Bulletin 313 



"III. Telia hypophyllous, at first arising from the uredinia, num- 

 erous, thickly scattered, small, 0.1 mm. or less across, few spores in 

 each sorus, ruptured epidermis inconspicuous; paraphyses none; 

 telioispores cylindrical, 23-26 by 64-100 /x, slightly or not narrowed 

 above or below, 8-11 (mostly 10) celled; wall blackish-brown, 3-7 /x 

 thick, closely and rather coarsely verrucose, the apex usually with 

 a conical hyaline j^apilla 10-12 /x long; pedicel rugose when dry, one 

 and a half length of spore, the upper half colorless, except near the 

 spore, 7 fx'in diameter, the lower part colorless, usually terete, swell- 

 ing in water, 16-20 fx in diameter. North American Flora, v. 7, p. 



167 (1912). 



939. Teleutospore, 1/12. 



Phragmidium obtusa (Strass.) Arthur. — On Potentilla canaden- 

 sis. Described by Arthur as follows : 



"O. Pycnia epiphyllous, in small crowded groups 0.1-.4 mm. 

 across, on slightly larger reddened and somewhat hypertrophied 

 spots, inconspicuous, in section globoid-lenticular 112-160 /x broad 

 by 35-50 fi high. 



*'II. Uredinia at first epiphyllous, surrounding the pycnia, in 

 crowded groups 0.5-1.3 mm. across, roundish or irregular, often con- 

 fluent into rings, at first bullate, soon naked, somewhat waxy; ure- 

 dinia afterward hypophyllous, scattered irregularly, round, 0.2-0.5 

 mm. across, early naked, slightly pulvinate, pulverulent, orange- 

 yellow, fading to dirty-white, ruptured epidermis noticeable; para- 

 physes usually wanting; uredinospores obovate or ellipsoid, 15-18 

 by 19-26 [x] wall pale-yellow, nearly colorless, thin, 1-1.5 fx, finely 

 verrucose-echinulate, points, 1-2 fx apart, the pores small, incon- 

 spicuous, 3 or 4, equatorial. 



III. Telia hypophyllous, scattered, round, 0.2-0.5 mm. across, 

 early naked, pulvinate, velvety, cinnamon-brown, ruptured epider- 

 mis inconspicuous ; teliospores cylindrical-clavate, or clavate-lance- 

 olate, 20-27 by 48-90 fx, rounded or obtuse above, obtuse or narrow- 

 ed below, slightly or not constricted at the septa, 3-5 celled; wall 

 cinnamon-brown, paler below, thin, 1-2 /x, thicker at apex, 5-8 fx; 

 smooth ; pedicel colorless, or tinted next to the spore, terete, 7-10 fx 

 in diameter, firm, with thick wall, one half to once length of spore." 



Note. In North Amercan Flora as Kuehneola obtusa, v. 7, p. 

 185 (1912). 



940. Uredospores, 1/12. 941. Teleutospores, 1/12. 



