250 NORTH AMERICAN FLORA [Volume 7 



51. Nigredo mexicana (Dietel & Holway) Arthur. 



Uromyces mexicanus Dietel & Holway ; Holway, Bot. Gaz, 24 : 24. 1897. 

 O and I. Pycnia and aecia unknown, 



II. Uredinia hypophyllous, more or less gregarious and crowded, roundish, 0.3-0.5- 

 mm. across, soon naked, cinnamon-brown, pulverulent, ruptured epidermis noticeable; 

 urediniospores broadly ellipsoid or globoid, 17-21 by 19-26 m; wall thin, 1-1.5 ju, golden- 

 brown, inconspicuously and rather sparsely echinulate, the pores 3 or 4, approximately 

 equatorial. 



III. Telia chiefly caulicolous, oblong or linear, often confluent, early naked, pulvinate, 

 firm, blackish, ruptured epidermis usually inconspicuous; teliospores ellipsoid or ovoid, 

 18-23 by 21-28 /x, often somewhat narrowed above; wall dark chestnut-brown, thick, 2.5- 

 3.5 Mi thicker above, 5-7 ju, with a somewhat paler umbo, very inconspicuously verruculose> 

 appearing smooth when wet; pedicel colorless, or slightly tinted next the spore, slender, 

 6-8 /i in diameter next the spore, becoming more slender below, two to four times the 

 length of spore. 



On Fabaceae : 



Meibomia sp. {Desmodium. sp.), Hidalgo, Jalisco, Mexico (state), Morelos, San Luis 

 Potosi. 



Type locality: City of Mexico, Mexico, on Desmodium sp. 

 Distribution : Central and southern Mexico. 



52. Nigredo tenuistipes (Dietel & Holway) Arthur. 



Uromyces tenuistipes Dietel & Holway; Holway, Bot. Gaz. 24: 25. 1897. 



O and I. Pycnia and aecia unknown. 



II. Uredinia chiefly hypophyllous, more or less gregarious and crowded, roundish, 

 0.3-0.5 mm. across, soon naked, cinnamon-brown, pulverulent, ruptured epidermis notice- 

 able ; urediniospores globoid or somewhat ellipsoid, 18-23 by 19-25 m*, wall golden-brown, 

 1.5-2 fx thick, inconspicuously and closely v err ucose- echinulate, the pores 3 or 4, approxi- 

 mately equatorial. 



III. Telia chiefly hypophyllous, scattered, roundish, 0.5-1 mm. across, soon naked, 



blackish, pulverulent, ruptured epidermis inconspicuous ; teliospores globose or somewhat 



ellipsoid, 20-24 by 23-27 /i; wall dark chestnut-brown, thick, 3^ju, minutely verruculose, 



appearing almost smooth when wet, the apex usually with a broad and very low pale umbo ; 



pedicel colorless, slender, tapering below, usually remaining, three to five times the length 



of spore. 



On Fabaceae : 



Meibomia strobilacea (Schlecht.) Kuntze {Desmodium strobilaceum Schlecht.), Jalisco, 

 Mexico (state), San Luis Potosi. 

 Type locality : l^slava, near City of Mexico, Mexico, on Desm-odium- sp. 

 Distribution : Central and southern Mexico. 

 KxsiCCATi ; Sydow, Ured. 1512. 



53. Nigredo'Indigoferae (Dietel & Holway) Arthur. 



Uromyces Indigoferae Dietel & Holway ; Holway, Bot. Gaz. 31 : 328. 1901. 



O and I. Pycnia and aecia unknown. 



II. Uredinia amphigenous, scattered, roundish, small, 0.3-0.5 mm. across, early naked, 

 somewhat pulverulent, slightly pulvinate, ruptured epidermis not noticeable ; uredinio- 

 spores ellipsoid or subgloboid, 15-19 by 19-25 ju ; wall cinnamon-brown, 1.5-2 ju thick, 

 rather finely echinulate, the pores 3, equatorial. 



III. Telia amphigenous, scattered, similar to the uredinia in shape and size, early 



naked, compact, pulvinate, blackish-brown, ruptured epidermis not noticeable; teliospores 



broadly ellipsoid or subglobose, 17-23 by 22-29 m» usually rounded above and below ; wall 



chestnut-brown, thick, 2.5-3.5 ju, thicker and somewhat lighter at apex, 7-10 ;u, smooth; 



pedicel hyaline, once to twice length of spore. 



On Fabaceae : 



Indigo/era leptosepala Nutt., Texas. 

 Indigofera mexicana Benth., Oaxaca. 

 Indigo/era mucronaia Spreng., Guatemala. 



