Part 5, 1920] AECIDIACEAE 345 
I. Aecia chiefly hypophyllous, in orbicular or elongate groups 2-5 mm. or more across, 
on larger discolored spots or on swollen areas on the stems, cupulate, low, 0.2-0.3 mm. in 
diameter; peridium delicate, the margin finely eroded and slightly recurved; peridial cells 
rhomboidal, 23-29 uv long, slightly overlapping, the outer wall thick, 5-8 w, striate, the inner 
wall thinner, 2~4 », verrucose; aeciospores globoid, often angular, 13-16 by 15-19 »; wall thin, 
1 or less, finely verrucose. 
On AMBROSIACEAE: 
Ambrosia trifida l,., Indiana, Missouri. 
Xanthium sp., Arkansas, Delaware, Indiana, Iowa, New Mexico, Oklahoma, Pennsylvania. 
II. Uredinia chiefly hypophyllous, scattered, oblong, 0.5-2 mm. long, tardily dehiscent by 
longitudinal slits, ruptured epidermis conspicuous, somewhat pulverulent, cinnamon-brown; 
urediniospores broadly ellipsoid or obovoid, 13-19 by 19-29 y; wall yellowish or cinnamon- 
brown, 1-2 » thick, moderately and finely echinulate, the pores 2, equatorial. 
III. Telia chiefly hypophyllous, scattered or more often confluent in groups 1-3 mm. or 
more long, individual sori linear, 0.1 mm. or less in width and surrounded by well developed 
brownish stroma, blackish or grayish-black, long covered by the epidermis, not or only slightly 
raised above the leaf surface; teliospores clavate-oblong, 15-21 by 39-64 yw, acuminate, obtuse 
or rounded above, narrowed below, slightly or not constricted at septum; wall dark cinnamon- 
brown, lighter toward base, about 1 » thick, much thicker above, 3-10 y; pedicel short, tinted. 
ON CYPERACEAE: 
Cyperus cylindricus (Ell.) Britton (C. Torreyi Britton), Delaware. 
Cyperus erythrorhizos Muhl., Missouri. 
Cyperus esculentus I,., California, Delaware, District of Columbia, Florida, Indiana, Kan- 
sas, Maryland, Michigan, Nebraska, New Jersey, New Mexico, Oklahoma, Texas; 
Mexico (state). 
Cyperus Fendlerianus Bock., New Mexico. 
Cyperus ferax I,. C. Rich., Cuba; Porto Rico. 
Cyperus giganteus Vahl, Porto Rico. 
Cyperus Hallii Britton, Missouri. 
Cyperus Houghtonii Torr., Nebraska, Wisconsin. 
Cyperus Mutisii.(H.B.K.) Griseb., Jamaica. 
Cyperus reticulatus L., Porto Rico. 
Cyperus rotundus J,., Florida, Kansas. 
Cyperus seslerioides H.B.K., Mexico (state). 
Cyperus speciosus Vahl, Indiana, Kansas. 
Cyperus strigosus I,., Alabama, Arkansas, Delaware, Illinois, Indiana, Iowa, Kansas, Louis- 
jana, Michigan, Mississippi, Nebraska, New York, Oklahoma, Pennsylvania, Vir- 
ginia, West Virginia, Wisconsin; Ontario. 
Cyperus surinamensis Rottb., Texas; Cuba. 
Cyperus thyrsiflorus Jungh.(?), Mexico (state). 
Cyperus sp., Colorado, North Carolina; Guatemala; Oaxaca. 
Typg LocaLtry: Bethlehem, Pennsylvania, on Cyperus sp. 
DisrrRrpution: New York to Michigan and Nebraska, and southward through Mexico, Cen- 
tral America, and the West Indies. 
Exsiccatt: Barth. Fungi Columb. 2449, 2758, 4260; Barth. N. Am. Ured. 136, 137, 233, 337, 
839, 1038, 1430, 1637; Carleton, Ured. Am. 10; Ellis, N. Am. Fungi 1018b; Ellis & Ev. Fungi Columb. 
552, 983, 1760, 2144, 2146; Ellis & Ev. N. Am. Fungi 3143, 3352; Seym. & Earle, Econ. Fungi 393. 
103. Dicaeoma Cyperi (Arth.) Kuntze, Rev. Gen. 37: 466. 1898. 
Puccinia Cyperi Arth. Bot. Gaz. 16: 226. 1891. 
Uredo ustulata Berk. & Curt.; Cooke, Grevillea 20: 110, hyponym. 1892. 
O and I. Pyenia and aecia unknown. 
II. Uredinia chiefly hypophyllous, scattered, often very numerous, oblong, 0.3-1.5 mm. 
long, tardily dehiscent by longitudinal slits, somewhat bullate; urediniospores ellipsoid or 
obovoid, 18-24 by 24-35 p; wall light cinnamon-brown, 1.5—2 » thick, moderately and finely 
echinulate, the pores equatorial, usually 3, in occasional spores 2 or 4. 
Ill. Telia chiefly hypophyllous, in groups 1~6 mm. long, or scattered, individual sori 
linear 0.1-0.2 mm. in width, with no or only slight development of stroma, somewhat tardily 
naked, dark chocolate-brown or blackish, pulvinate, ruptured epidermis conspicuous; telio- 
spores broadly clavate-oblong, 18-26 by 35-61 p», rounded or truncate above, narrowed below, 
slightly constricted at septum; wall chestnut-brown, paler below, about 1-1.5 » thick, much 
thicker above, 7-12 4, smooth; pedicel short, tinted. 
On CYPERACEAE: 
Cyperus atropurpureus Liebm., Mexico (state). 
Cyperus Buckleyi Britton, Michoacan. 
