Arthur: Uredinales of Costa Rica 127 



44. Uromyces Montanoae Arthur & Holway sp. nov. (on 



Carduaceae) 



Montanoa dumicola Klatt, San Jose, Dec. 11, 1915, II, III, 251 ; 

 same, Jan. 18, 1916, II, 444; Tres Rios near San Jose, Dec. 

 20, 191 5, II, 2/3. 

 Montanoa sp., San Jose, Jan. 3, 1916, II, 355; San Ramon, Jan. 

 14, 1916, II, 4^7. 



Uredinia hypophyllous, scattered, round or oblong, 0.1-1 mm. 

 across, early naked, pulverulent, cinnamon- or light chestnut- 

 brown, ruptured epidermis evident ; urediniospores when viewed 

 with pores in optical section obovoid-triangular, 23-24 by 23-28 /x, 

 with pores in central part obovoid or ellipsoid, narrower, 19-23 by 

 23-28 fx; wall cinnamon-brown, thin, 1-1.5/x, moderately echinu- 

 late, the pores 2, equatorial. 



Telia hypophyllous, scattered, round, 0.3-0.5 mm. across, early 

 naked, compact, dark cinnamon-brown, becoming cinereous from 

 germination, ruptured epidermis inconspicuous ; teliospores nar- 

 rowly obovoid or ovoid, 18-21 by 29-40 /x, rounded at both ends 

 or narrowed below ; wall cinnamon-brown, thin, 1 j a, much thicker 

 above, 4-7 fi, smooth ; pedicel colorless or yellowish, as long as or 

 shorter than the spore. 



The species much resembles Uromyces bidenticola, but differs 

 in having urediniospores with thinner walls, equatorial pores, and 

 triangular form in certain positions. The teliospores often ger- 

 minate at maturity, even in evident genetic connection with the 

 uredinia. It is possible the same thing may occur in U. bidenti- 

 cola. 



The type for the species is a collection made by Professor Hol- 

 way on Montanoa Pittieri Robs. & Greenm., in Guatemala, at 

 San Lucas Toliman, 5100 feet alt., Dept. Solola, Feb. 2, 191 5, 

 II, III, 176. 



45. Uromyces cucullatus Sydow (on Carduaceae) 

 Zexmenia aurantiaca Klatt. 



The species, which is common in Mexico on a variety of hosts, 

 was founded on a Costa Rican specimen sent to Sydow by Neger, 

 which appears to have been taken from a phanerogamic collec- 

 tion made by A. Tonduz at Rio Visilla, Prov. San Jose, alt. 1,100 

 meters, represented in the herbarium Nat. Cost. 9836. A speci- 



