Part 5, 1920] AECIDIACEAE 399 
ellipsoid or obovoid, 19-28 by 23-30 u; wall yellowish or cinnamon-brown, 2-4 u thick, sparsely 
and evenly echinulate, the pores 2 or 3, equatorial, often indistinct. 
III. Telia amphigenous, scattered or confluent in small groups of two or three, roundish 
or irregular, up to 0.4 mm. across, early naked, pulverulent, chestnut-brown, ruptured epidermis 
rather inconspicuous; teliospores ellipsoid, 19-26 by 28~42 u, rounded above and below, slightly 
constricted at septum; wall dark cinnamon-brown, uniformly thick, 1.5-2 #, reticulate with 
meshes about 1 » in diameter, giving the appearance of being minutely and closely verrucose, 
the pore of upper cell usually apical, of lower cell depressed often near pedicel; pedicel hyaline, 
shorter than spore, fragile. 
On AMMIACEAE: 
Sanicula canadensis L,., West Virginia. 
Sanicula floridana Bickn., Florida. 
Sanicula marylandica I,., Saskatchewan. 
Sanicula sp., Delaware, Indiana, Iowa, Missouri, New York, Pennsylvania, South Caro- 
lina, South Dakota, Wisconsin; British Columbia, Quebec. 
TYPE LocaLity: North America [Wisconsin?], on Sanicula marilandica. 
DISTRIBUTION: Quebec southward to Florida and westward to the foothills of the Rocky Moun- 
tains, as well as in British Columbia. 
ILLUSTRATIONS: Holway, N. Am. Ured. 1: pl. 37, f. 125a, b, c. 
Exsiccatl: Barth. N. Am. Ured. 765; Rav. Fungi Car. 4: 90. 
191. Dicaeoma Arracacharum (Lindr.) Arthur. 
Caeoma Arracacharum Lindr. Medd. Stockh. Hégsk. Bot. Inst. 49:1. 1901. 
Puccinia Arracachae Lagerh. & Lindr.; Lindr. Medd. Stockh. Hégsk. Bot. Inst. 49:5. 1901. 
Puccinia Arracacharum Arth. Am. Jour. Bot. 5: 476, 1918. 
O. Pycnia usually epiphyllous, few, in small groups 0.1-0.3 mm. in diameter, noticeable, 
chestnut-brown, globoid, 150-220 « in diameter; ostiolar filaments 80-96 » long, not projecting 
beyond the ostiole. 
I. Aecia amphigenous, in groups of 2-6 with the pycnia, round, very small, 0.1 mm. or 
less in diameter; peridium wanting, the aecia bounded by a thin layer of mycelium; aeciospores 
angularly ellipsoid or oblong, 18-23 by 24-35 y; wall colorless, 2-2.5 » thick, variably verrucose, 
sometimes appearing echinulate. 
II. Uredinia hypophyllous, scattered, round, 0.2-0.5 mm. across, early naked, pulveru- 
lent, yellow or pale cinnamon-brown, ruptured epidermis evident; urediniospores ellipsoid or 
obovoid, 18-24 by 29-37 »; wall colorless or yellowish, moderately thick, 1.5-2.5 u, closely 
echinulate, the pores obscure. 
III. Telia hypophyllous, scattered, round, 0.4-0.6 mm. across, early naked, pulvinate, 
chestnut-brown, ruptured epidermis inconspicuous; teliospores ellipsoid or oblong, 21-29 by 
34-51 yp, rounded above, slightly narrowed below, slightly constricted at septum, germinating 
at maturity; wall cinnamon-brown, thin, 1-2 », thickened at apex, 5-10 », smooth; pedicel 
colorless, up to one and a half times length of spore, tapering toward the base. 
On AMMIACEAE: 
Arracacia bracteata Coult. & Rose, Guatemala. 
TYPE LocaLity: Ecuador, on Arracacia sp. : 
DIstRIBuTION: Guatemala; also in South America. 
192. Dicaeoma obscuratum (Arth. & Holway) Arthur. 
Puccinia obscurata Arth. & Holway; Arth, Am. Jour. Bot. 5:477. 1918. 
Oand I. Pyecnia and aecia unknown. 
II. Uredinia usually hypophyllous, scattered, round or oval, 0.1-0.8 mm. across, early 
naked, pulverulent, pale cinnamon-brown, ruptured epidermis evident; urediniospores globoid 
or obovoid, 18-26 by 24-29 yu; wall colorless or light-yellow, moderately thick, 1.5-2.5 yu, closely 
echinulate, the pores 2 or 3, usually 2, equatorial, rather indistinct. 
III. Telia hypophyllous, scattered, round, 0.1-0.3 mm. across, early naked, somewhat 
pulverulent, chestnut-brown, ruptured epidermis evident; teliospores broadly ellipsoid or 
oblong, 23-31 by 30-40 4, rounded above and below, slightly or not constricted at septum; 
wall cinnamon-brown, thin, 1-1.5 », thickened at apex, 3-7 », smooth; pedicel colorless, fragile, 
longer than spore. 
