296 NORTH AMERICAN FLORA [VoLuME 7 
Mahonia diversifolia Sweet (Berberis Aquifolium Lindl.) (cult.), Michigan; Quebec. 
Meahonia Swaseyi (Buckl.) Fedde (Berberis trifolia Schultes, Odostemon Swaseyi A. Heller) 
(cult.), Mexico (state). 
Mahonia trifoliolata (Moric.) Fedde (Berberis trifoliolata Moric.), proven by culture, but not 
yet collected in the field. 
II. Uredinia caulicolous or epiphyllous, numerous, crowded and often confluent, oblong- 
linear, 1-5 mm. long, reddish-brown, pulverulent, opening by a lateral rupture of the epidermis 
which often remains attached at one side as a conspicuous flap; urediniospores oblong, some- 
times ellipsoid, 13-24 by 21-42 u; wall golden-brown at maturity, 1.5-2 » thick, sometimes 
slightly thicker at apex, conspicuously and moderately echinulate, the pores 4, rarely 5, 
equatorial. 
III. Telia chiefly caulicolous, numerous, crowded and often confluent in lines, oblong, 
1-5 mm. long, blackish-brown, compact, soon naked by the lateral rupture of the epidermis, 
ruptured epidermis conspicuous; teliospores ellipsoid or oblong-clavate, 16-23 by 35-58 u, 
rounded or obtuse above, usually narrowed below, moderately constricted at septum; wall 
dark chestnut-brown above, paler below, 1-1.5y thick, thicker at apex, 5-104; pedicel 
persistent, golden-brown at the attachment, fading to colorless at base, as long as spore or 
longer. 
Specialization in this species has received much greater attention than in any other species 
of the Uredinales (cf. Kleb. Wirtsw. Rostp. 205-236. 1903). Impetus was given to such 
studies by the classical investigations of Eriksson (Ber. Deuts. Bot. Ges. 12: 292~312. 1892). 
Much work has been done in North America as well as elsewhere, of which none is more 
prominent than that by Stakman and his co-workers (cf. Jour. Agr. Res. 10: 429-495. 1917). 
The races are many and are based largely upon the behavior of the urediniospores. The most 
sharply defined race is that upon Phieum pratense, which also shows a morphological differ- 
ence in the smaller’size of the urediniospores and mycelium. 
ON POACEAE: 
Achyrodes aureum (L.) Kuntze (Lamarckia aurea Moench), California. 
Aegilops sp., Minnesota. 
Agropyron caninum (L.) Beauv. (Triticum caninum I,.), California, Colorado, Minnesota, 
New York, North Dakota, South Dakota, Utah, Wisconsin, Wyoming; Manitoba. 
Agropyron dasystachyum (Hook.) Scribn., Montana, Oregon. 
Agropyron pseudorepens Scribn. & Smith, Colorado, Nebraska, North Dakota. 
Agropyron repens (1,.) Beauv. (Triticum repens \1,.), Indiana, Iowa, Kentucky, Maine, 
Massachusetts, Michigan, New York, North Dakota, Pennsylvania, South Dakota, 
Vermont, Wisconsin; Ontario. 
Agropyron Richardsoni (Trin.) Schrad., North Dakota, South Dakota. 
Agropyron Smithii Rydb. (A. occidentale Scribn.), Colorado, Nebraska, New Mexico, North 
Dakota, South Dakota, Wyoming; Manitoba. 
Agropyron tenerum Vasey, Colorado, Iowa, Michigan, Minnesota, Montana, Nebraska, 
New Mexico, North Dakota, South Dakota, Utah, Wyoming; Manitoba. 
Agrostis alba L. (A. vulgaris With.), California, Connecticut, Delaware, Indiana, Iowa, 
Maine, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New York, Ohio, 
Oklahoma, Rhode Island, South Dakota, Vermont, Virginia, West Virginia, Wisconsin; 
Ontario, Quebec. 
Agrostis diegoensis Vasey, California. 
Agrostis exavata Trin., Montana, Nebraska, Oregon. 
Agrostis hyemalis (Walt.) B.S.P. (A. scabra Willd.), Iowa, Maine, Massachusetts, Minne- 
sota, Wisconsin. 
Agrostis maritima Lam. (A. alba maritima Meyer), Nova Scotia. 
Agrostis perennans (Walt.) Tuckerm., Connecticut, Maine; New Brunswick, Nova Scotia. 
Alopecurus aristulatus Michx. (A. fuluus J. G. Smith, A. geniculatus aristulatus Torr.), 
Indiana, Wisconsin. 
Alopecurus californicus Vasey, Oregon. 
Alopecurus pratensis L., Minnesota, South Dakota. 
Anthoxanthum aristatum Boiss., Mississippi. 
Anthoxanthum odoratum 1,., Delaware, Maine, New Jersey, New York; Nova Scotia. 
Arrhenatherum elatius (L.) Beauv. (A. avenaceum Beauv.), Indiana, Washington. 
Avena barbata Brot., California. 
Avena faiua L., California, Iowa, Montana, New Mexico, North Dakota, South Dakota, 
Washington; Manitoba; Mexico (state). 
Avena fatua glabrata Peterm., Oregon. 
Avena sativa 1,., California, Colorado, District of Columbia, Illinois, Indiana, Iowa, Kan- 
sas, Maine, Maryland, Michigan, Minnesota, Missouri, Montana, Nebraska, New 
Mexico, New York, North Dakota, Oregon, Oklahoma, South Dakota, Texas, Utah, 
Virginia, West Virginia, Wisconsin; Ontario. 
Beckmannia erucaeformis (L,.) Host, Oregon, Utah. 
Briza maxima 1., Minnesota, Wisconsin. 
Briza minor L.. Ontario 
Bromus jasonicus Thunt. Colorado. 
Bromu polyanthui So itn, Montara 
