102 NORTH AMERICAN FLORA {[VoLUME 7 
II. Uredinia amphigenous and caulicolous, scattered or somewhat gregarious, often 
crowded, round or on stem elongate, 0.3-0.5 mm. across, soon naked, reddish-yellow 
fading to nearly white, pulvernlent, ruptured epidermis noticeable ; urediniospores broadly 
elliptical or obovate, 13-18 by 15-25 #, wall colorless, rather thin, 24, evenly and finely ver- 
rucose, with low papillae, pores equatorial, obscure; paraphyses intermixed with the 
spores, capitate, large, 15-22 by 40-652, smooth, wall thick. 
III. Telia amphigenous and caulicolous, scattered, often confluent, round or elongate, 
0.2-0.5 mm. across, slightly elevated, reddish-brown becoming blackish; teliospores sub- 
epidermal, appressed into a single layer, prismatic, 1-celled, 10-20 by 42-50; wall brown, 
smooth, thin, about 1#, not thickened above. 
ON LINACEAE : 
Linum Breweri A. Gray; California. 
Linum congestum A, Gray, California. 
Linum drymarioides Curran, California. 
Linum Lewisit Pursh (L. perenne Nutt.), Arizona, California, Colorado, Montana, 
Nebraska, Nevada, New Mexico, Oregon, Utah, Wyoming. 
Linum rigidum Pursh, Kansas, Montana, Nebraska. 
Linum sulcatum Ridd., lowa, Wisconsin. 
Linum usitatissimum I,., lowa, North Dakota; Ontario. 
TYPE LOCALITY : Island of Zealand, Denmark, on Linum catharticum. 
DISTRIBUTION : Throughout the northern United States and Canada, and southward in the 
Rocky Mountains; also in South America, Australia, and Europe. 
ExsiccaTi: Seym. & Earle, Econ. Fungi 8 6; Ellis & Ev. N. Am. Fungi 3567 ; Griff. West 
Am. Fungi 249, 249a ; Ellis & Ev. Fungi Columb. 1718, 1832 ; Sydow, Ured. 1846, 1949. 
EXCLUDED SPECIES 
Melampsora Liguidambaris Cooke, Grevillea 6: 138. 1898. On Liguidambar Styra- 
ciflua \,. Some fungus tmperfectus, possibly a Phoma. 
2. PHYSOPELLA Arth. Résult. Sci. Congr. Bot. Vienne 338. 1906. 
Cycle of development imperfectly known; only uredinia and telia recognized, both 
subepidermal. 
Uredinia erumpent, definite, roundish, pulverulent, encircled by more or less clavate 
paraphyses, often united by their bases, or wholly, into a pseudoperidium opening by a 
central pore. Urediniospores borne singly on pedicels, obovate-globoid or ellipsoid ; wall 
pale-yellow, echinulate, or rarely verrucose, pores obscure. 
Telia indehiscent, forming lenticular masses, two or more cells thick at center. 
Teliospores one-celled; walls smooth. 
Type species, Uredo Vitis Thiim. (on Vitis vinifera). 
Urediniospores echinulate. 
Paraphyses free. 
Paraphyses incurved, hyphoid, firm. 1. P. Vids. 
Paraphyses incurved, clavate, thick-walled. 2. P. ficina. 
Paraphyses erect, hyphoid, delicate. 3. P. Fict. 
Paraphyses compressed into a pseudoperidium. 4. P. Artocarpt. 
Urediniospores minutely verrucose ; paraphyses imbricated into a pseudo- 
peridium. 
1. Physopella Vitis (Thiim.) Arth. Résult. Sci. Congr. Bot. 
Vienne 338. 1906. 
Uredo Vitis Thiim. Pilze Weinst. 182. 1878. 
Uredo Vialae Lagerh. Compt. Rend. Acad. Sci. Paris 110: 729. 1890. 
Uredo Viticis Juel, Bih. K. Sv. Vet.-Akad. Hand]. 23(3)1°: 26. 1897. 
Phakopsora Vitis Sydow, Hedwigia Beibl. 38: 141, 1899. 
II. Uredinia hypophyllous, scattered thickly over wide areas, round, minute, 0.1 mm. 
or less across, soon naked, arising between epidermis and mesophyl, surrounded by num- 
erous incurved paraphyses, pulverulent, pale-yellow, fading to dirty-white, ruptured epi- 
dermis inconspicuous; urediniospores broadly ellipsoid or obovate, 13-17 by 18-27; wall 
nearly colorless, thin, 1#, minutely and rather closely echinulate, pores obscure; para- 
physes hyphoid, curved and irregular, 6-104 thick, 30-60 long, wall uniformly thin, 1p, 
yellowish. 
on 
. P. Aeschynomenis. 
