466 NORTH AMERICAN FLORA [VoLumE 7 
3.5-4 » thick, 10-13 4 thick above with a semi-hyaline umbo, sparsely and coarsely tubercu- 
late; pedicel tinted next to spore, up to twice length of spore. 
On CONVOLVULACEAE: 
Exogonium arenarium Choisy (Ipomoea arenaria Steud., I. Steudelii Millsp.), St. Thomas. 
TyPE Locatity: Boca del Riachuelo, Argentina, on Ipomoea acuminata. 
DistTRIBUTION: West Indies; also in South America. 
24. Allodus crassipes (Berk. & Curt.) Arth. Résult. 
Sci. Congr. Bot. Vienne 345. 1906. 
Puccinia crassipes Berk, & Curt. Grevillea 3:54. 1874. 
?Aecidium Convolvulinum Speg. Revista Argent. Hist. Nat. 1:398. 1891. 
Puccinia Ipomoeae Cooke; Lagerh. Tromsé Mus. Aarsh.17: 61. 1895. 
Dicaeoma crassipes Kuntze, Rev. Gen. 33: 468. 1898. 
Dicaeoma Ipomoeae Kuntze, Rev. Gen. 33: 469. 1898. 
O. Pycnia not seen. 
I. Aecia chiefly hypophyllous, gregarious, often distributed over the entire leaf, varying 
greatly in size and distribution, circular in outline except when on the veins, short-cylindric, 
0.2-0.4 mm, in diameter; peridium colorless, erose; peridial cells rhomboidal, 14-21 by 30~42 y, 
the outer wall finely striate, 3-4 4 thick, the inner wall rather coarsely verrucose, 3-6 u thick; 
aeciospores globoid, 16-22 by 19-26 yw; wall colorless, 1~1.5 w thick, finely verrucose. 
III. Telia amphigenous, grouped about the aecia or less commonly scattered, often con- 
fluent, circular in outline, 0.2-0.4 mm. across, early naked, chocolate-brown, pulvinate, slightly 
pulverulent, ruptured epidermis conspicuous; teliospores ellipsoid, 24-32 by 39-61 uw, usually 
rounded at both ends; wall dark chestnut-brown, 3-4 « thick, 6-9 » thick above with a semi- 
hyaline umbo, conspicuously and usually coarsely verrucose; pedicel tinted next to spore, stout, 
up to one and one half times length of spore. 
On CONVOLVULACEAE: 
Ipomoea cathartica Poir. (J. acuminata R. & S. not R. & P., Pharbitis cathartica Choisy), 
Cuba 
Ipomoea glabriuscula House, Guatemala. 
Ipomoea purga (Wender.) Hayne (I. jalapa Nutt. & Coxe), Costa Rica; Oaxaca. 
Ipomoea purpurea (L.) Roth, Morelos. 
Ipomoea tiliacea (Willd.) Choisy (1. fastigiata Sweet), Guatemala. 
Ipomoea trichocarpa Ell. (I. carolina Pursh, I. commutata R. & S.), Florida, Georgia, 
Louisiana, South Carolina, Texas. 
Ipomoea irifida (H.B.K.) G. Don, Costa Rica. 
Ipomoea iviloba L,., Florida; Cuba; Mona Island; Porto Rico; St. Croix. 
TYPE LOCALITY: Santee Canal, South Carolina, on Ipomoea trichocarpa. 
DistrRipuTIon: South Carolina to Texas, Central America, and the West Indies; also in South 
America. 
ee Exsiccati: Barth. Fungi Columb. 2456, 4853; Barth. N. Am. Ured. 1805; Rav. Fungi Am. 
25, Allodus megalospora Orton, Mem. N. Y. 
Bot. Gard. 6: 198. 1916. 
Puccinia megalospora Arth. & Johnston, Mem. Torrey Club 17: 152. 1918. 
Puccinia macrocephala Speg. Bol. Acad. Nac. Ci. Cordoba 23: 445. 1919, 
O. Pycnia not seen. 
I. Aecia chiefly hypophyllous, occurring singly or in small groups, cylindric, 0.2-0.5 mm. 
in diameter; peridium white, erose at first, soon becoming lacerate, up to 0.6 mm. high; peridial 
cells rhombic or rhomboidal, 16-25 by 31-45 yu, the outer wall 4-6 uw thick, striate, the inner 
wall 6-10» thick, rather coarsely verrucose; aeciospores globoid or broadly ellipsoid, 19-28 
by 23-34 «; wall colorless, 1.5—2 » thick, finely and closely verrucose. 
III. Telia chiefly epiphyllous, occurring singly or in groups, often arising opposite or 
around and among the aecia, circular in outline, 0.2-0.6 mm. in diameter, early naked, often 
becoming confluent and forming large sori, up to 5 mm. across, pulvinate, pulverulent, blackish- 
brown, ruptured epidermis rather conspicuous; teliospores ellipsoid, 23-32 by 48-70 yw, narrowed 
or rounded above, rounded below, slightly constricted at septum; wall vinous- or chocolate- 
brown, 3—4 yw thick, rather coarsely verrucose, 9-15 « thick above, nearly concolorous, somewhat 
paler at apex; pedicel tinted next to spore, stout, up to 115 « long. 
