Part 7, 1922] AECIDIACEAE 533 
occasionally scattered on the upper surface, round, 0.5—0.8 mm. across, early naked, cinnamon- 
or chestnut-brown, becoming cinereous from germination, ruptured epidermis noticeable; 
teliospores oblong or oblong-clavate, occasionally ellipsoid, 16-24 by 30-60, rounded or 
obtuse above, rounded or more commonly narrowed below, not or slightly constricted at 
septum; wall nearly colorless or chestnut-brown, 1.5—2 » thick, 5-8 » above, smooth or ob- 
scurely striate; pedicel colorless, persistent, once to twice length of spore. 
This species is correlated with Dicaeoma monoicum (Peck) Arth. & Fromme and Allodus 
consimilis (Ellis & Ev.) Orton, the morphological characters of like stages in the three species 
being similar or identical, and the hosts of the aecial stage of the heteroecious species cor- 
responding with the hosts of the two autoecious species. This agreement doubtless indicates 
a common origin for the three species. 
On BRASSICACEAE: 
Arabis ambigua DC., Alaska. 
Arabis arcuata A. Gray, California. 
Arabis Breweri S. Wats., California. 
Arabis canescens Nutt., Nevada. 
Arabis Crandallit B. L. Robinson, Colorado. 
Arabis divaricarpa A. Nelson, Idaho; Alberta. 
Arabis Drummondii A. Gray, Montana; British Columbia. 
Arabis exilis A. Nelson, Colorado, Montana. 
Arabis furcaia S. Wats., Washington. 
Arabis Holboellit Hornem., Greenland. 
Arabis lignipes A. Nelson, Alberta. 
Arabis Lyallit S. Wats., Montana, Washington; British Columbia. 
Arabis lyrata occidentalis S. Wats., Alaska. 
Arabis microphylla Nutt., California, Idaho. 
Arabis perennans S. Wats., California. 
Arabis retrofracta Graham (A. Holboellit Am. Auth.), Oregon, Utah. 
Cheiranthus pygmaeus Adams, Grinnell Land. 
Drabea spectabilis Greene, Colorado, Utah. 
Schoenocrambe linifolia (Nutt.) Greene (Sisymbrium linifolium Nutt.), Montana, Utah, 
Wyoming. 
Schoenocrambe pinnata Greene, Colorado. 
Smelowskia Fremontii S. Wats., Nevada. 
TYPE LocaLity: Greenland, on Arabis Holboellit. 
DistrRiBurion: Central Colorado to southern California northward to Alberta and south- 
western Alaska, and from Greenland to Grinnell Land. 
InLustrRations: Bull. Lab. Nat. Hist. Univ. Iowa 3?: pl. 3, f. 17a, b; Fl. Dan. pl. 2220; Hol- 
way, N. Am. Ured. 1: pl. 15, f. 63a, pl. 16, f. 63b-g, pl. 17, f. 63h-Z. . 
Exsiccatr: Arth. & Holway, Ured. Exs. Ic. 17a, b; Barth. N. Am. Ured. 149; Ellis, N. Am. 
Fungi 1834; Ellis & Ev. N. Am. Fungi 2889b, 2891; Garrett, Fungi Utah. 4; Sydow, Ured. 1926. 
25. Micropuccinia Cruciferarum (Rudolphi) Arth. & Jackson; 
Arth. Bull. Torrey Club 48: 40. 1921. 
Puccinia Cruciferarum Rudolphi, Linnaea 4: 391. 1829. 
Puccinia Cardamines Niessl, Verh. Nat. Ver. Brinn 10: 164. 1872. 
Puccinia Cardamines-bellidifoliae Dietel, Bot. Jahrb. 27: 4. 1899. 
Dasyspora Cruciferarum Arth. Résult. Sci. Congr. Bot. Vienne 346. 1906. 
O. Pycnia unknown. 
Ifl. Telia amphigenous and petiolicolous, scattered or solitary, round, 0.5—2 mm. across, 
rarely confluent, often elongate when petiolicolous, early naked, becoming pulverulent, chest- 
nut-brown, ruptured epidermis conspicuous; teliospores oblong or ellipsoid, 14-18 by 30-38 u, 
rounded or obtuse above, rounded or occasionally narrowed below, noticeably constricted 
at septum; wall dark cinnamon-brown, 1-2», with sub-hyaline umbo at apex, 3-5 yw thick, 
finely verrucose; pedicel colorless, usually deciduous. 
On BRASSICACEAE: 
Cardamine bellidifolia L., Greenland; British Columbia. 
Cardamine cordifolia A. Gray, Wyoming. eee 
TYPE LOCALITY: Scandinavia, on Cardemine bellidifolic. . 
DIstRiBuTION: Southern Wyoming to British Columbia and Greenland; also in Europe. 
JLLUSTRATION: Beitr. Krypt. Schweiz 2?: f. 104. 
26. Micropuccinia aberrans (Peck) Arthur & Jackson. 
Puccinia aberrans Peck, Bot. Gaz. 4: 217. 1879. 
Dicaeoma aberrans Kuntze, Rev. Gen. 34: 467. 1898. 
O. Pycnia amphigenous, scattered over large areas, preceding or among the telia, puncti- 
