Arthur: Uredinales of Porto Rico 
195 
of the material resembles Melanthera deltoides, and some M. 
hastata ciihensis, but the careful study given to the whole set by 
Mr. Percy Wilson of the New York Botanical Garden, in which 
he was assisted by other members of the staff, makes it seem 
best to assign all the Stevens collections to M. canescens. 
34. Uromyces Bidentis Lagerh. Bull. Soc. France ii : 213. 
1895. 
Uredo Bidentis P. Henn. Hedwigia 35: 251. 1896. 
Uredo hidenticola P. Henn. Hedwigia 37: 279. 1898. 
Uredo amaniensis P. Henn. Engler’s Bot. Jahrb. 38: 106. 
1905. 
On Carduaceae: 
Bidens leucantha Willd., Santurce, Jan. 22, 2<5p, Tune 5, 
277(5; Vega Baja, Feb. 20, 470, May 21, 1731, Nov. 5, 
4280-, Aibonito, June 5, 2146; Anasco, Oct. 12, 5532; 
Mayagiiez, Oct. 31, JP52; Monte Alegrillo, without 
date, 4713; Lares, Nov. 22, 4927-, Aguada, Nov. 22, 
3093-, River junction below Utuado, Dec. 30, 6383. 
Cosmos caiidafus H.B.K., Barros, Jan. 2, II, 63; Jayuya, 
Dec. 17, II, 3988. 
IMost of the Stevens collections show uredinia only. It has 
been collected in Porto Rico also by E. W. D. Holway, San Juan, 
January, 1911, showing both uredinia and telia. 
Specimens of the species have been seen from Martinique on 
B. leucantha, Hahn, and on B. pilosa, Sieber, and from Jamaica 
on B. leucantha, Underwood 1749, Holway 214, and on Cosmos 
caudatus, Underwood 1149. 
The type collection is on Bidens andicola, near Quito, Equador, 
Lagerheim, and has not been seen by the writer. A collection 
on the same host from Guatemala, December, 1887, J. J. Cooper, 
shows uredinia and telia. 
The species is autoecious, and what is often called a hemi- 
uromyces, showing ordinarily only uredinia and telia. How- 
ever, on collections by E. W. D. Holway, on B. tereticaulis, Jalapa, 
Mexico, 3210 (Barth. N. Am. Ured. 782), and Oaxaca, Mexico, 
3667, and also by E. L. Stevens, on B. pilosa, Caracas, Venezuela, 
