Part 3, 1912] AECIDIACKAB 167 



below, 6-9-celled; wall dark chocolate-brown, 5-6// thick, closely and rather coarsely ver- 



rucose, the apex with -a conical hyaline papilla 8-11 fi long ; pedicel about length of spore, 



rugose when dry, the upper half colorless except near the spore, 7-10 fi in diameter, the 



lower part colorless, swelling in water to broadly clavate, 18-26 fi at broadest diameter. 

 On Rosace a.e: 



Rubacer parvifiorum (Nutt.) Rydb. {Rubus nuikanus Moc, R. parviflorus Nutt.), Cali- 

 fornia, Colorado, Idaho, Minnesota, Montana, New Mexico, Oregon, Washington, 

 Wisconsin, Wyoming; British Columhia. 

 Type locality : Mountains near Pagosa Peak, Colorado, on Rubus nuikanus. 

 Distribution : Mountainous region from central New Mexico and central California north- 

 ward into Canada. 



ExsiccATi : Sydow, Ured. 1788, 1789 ; Ellis & Ev. N. Am. Fungi 3245 ; D. Griff. W. Am. Fungi 



2U, 329 ; Seym. & Earle, Econ. Fungi 34; Earth. N. Am. Ured. 115 ; Earth. Fungi Columb. 2747, 

 3156. 



5. Phragmidium americanum Dietel, Hedwigia 44 : 124. . 1905. 



Phragmidium mucronatum americanum Peck, Ann. Rep. N. Y. State Mus. 28: 86. 1876. 



0. Pycnia chiefly epiphyllous, usually few, gregarious and often confluent, inconspic- 

 uous, subcuticular and extending downward between the cells, pale honey-yellow, low- 

 conoidal or discoidal, 80-125// broad by 30^0 /^ high. 



1. Aecia chiefly hypophyllous or petiolicolous, usually compound or confluent, forming 

 sori of irregular outline, 1-5 mm. across, applanate, bright orange-yellow fading to pale- 

 yellow, ruptured epidermis usually noticeable ; paraphyses rather numerous but inconspic- 

 uous, surrounding each individual sorus, erect, not exceeding the height of the spore-mass, 

 clavate, 10-20 by 38-50 /ti, the wall evenly thin, 1/^, nearly or quite colorless, smooth; aecio- 

 spores broadly ellipsoid or globoid, small, 18-20 by 20-26 (U; wall pale-yellow, rather 

 thin, 1-1.5 /i, finely and closely verrucose with well-separated papillae. 



II. Uredinia hypophyllous, numerous, thickly scattered, round, small, 0.1 mm. or less 

 across, early naked, ruptured epidermis inconspicuous ; paraphyses encircling the sorus, 

 abundant and conspicuous, strongly incurved, cylindrical or somewhat clavate, 9-13 by 

 30-55 /i, the wall evenly thin, 1 // or less, nearly or quite colorless, smooth ; urediniospores 

 obovate-globoid, small, 15-18 by 18-20 /*; wall pale-yellow, thin, 1 //, rather closely ver- 

 rucose- echinul ate, the pores indistinct, small, scattered, 8 or more. 



III. Telia hypophyllous, at first arising from the uredinia, numerous, thickly scattered, 

 small, 0.1 mm. or less across, few spores in each sorus, ruptured epidermis inconspicuous; 

 paraphyses none; teliospores cylindrical, 23-26 by 64-100 /^, slightly or not narrowed above 

 or below, 8-11- (mostly 10-) celled; wall blackish-brown, 3-7 /^ thick, closely and rather 

 coarsely verrucose, the apex usually with a conical hyaline papilla 10-13 ^i long ; pedicel 

 rugose when dry, once and a half length of spore, the upper half colorless except near the 

 spore, 7/i in diameter, the lower part colorless, usually terete, swelling in water, 16-20 /i in 



diameter. 



The telia of this species in some collections much resemble those of Phragmidium Rosae-acicu- 

 laris. In general the several species of the genus Phragmidium, occurring on roses show so much 

 variation that it is often necessary in order to determine species as here defined to take into account 

 not only the morphological characters of the fungus but also the physical features of the host and 

 the geographic location. 

 On Rosaceae : 



Rosa blanda Ait., Vermont ; Ontario. 

 Rosa humilis Marsh., Delaware, New York. 



Rosa virginiana Mill. (i?. lucida Ehrh.), Maine, Massachusetts, New Jersey ; Nova Scotia. 

 Rosa sp. cult.. District of Columbia, Indiana, Iowa, Kentucky, Massachusetts, Nebraska, 

 New Jersey, New York, West Virginia, Wisconsin ; Ontario. 

 Type locality: North America, on Rosa blanda. 



Distribution : Delaware to southern Ontario and northeastward to Nova Scotia on native 

 roses and locally on cultivated roses from the northern Atlantic coast as far west as central 



ExsiCCATi : Ellis, N. Am. Fungi 276, 1065 ; Ellis & Ev. Fungi Columb. 2132 ; Seym. & Earle, 

 Econ. Fungi J(5; Shear, N. Y. Fungi (56, 122. 



Illustrations : Torreya 9 : 22, /. / ; Hedwigia 44 : pi. 4, f. 5. 



6. Phragmidium Rosae-setigerae Dietel, Hedwigia 44 : 125. 1905. 



O. Pycnia chiefly epiphyllous, gregarious, usually few, in small groups opposite the 

 aecia often somewhat confluent, inconspicuous, subcuticular, extending into the lateral 

 walls' of the epidermal cells, pale honey-yellow, discoidal, 100-160/^ in diameter by 30-40^ 



high .•- 



