﻿588 Arthur: New species of Uredineae 



I. Aecia amphigenous, in oval groups 1-4 mm. long on brown- 

 ish spots, when mature falling away leaving the ruptured epidermis 

 conspicuous; peridium delicate, deeply lacerate, recurved, the 

 peridial cells lanceolate, rarely somewhat rhomboidal, pointed, 

 40-60 fjL long, the outer wall 3-5 m thick, smooth and transversely 

 striate, the inner wall somewhat thinner, verrucose; aeciospores 

 globoid, 23-27 by 24-34 m; wall colorless, 2-3 m thick, finely 



III. Telia amphigenous, scattered, often immediately outside 

 or within the aecial cups, rather tardily naked by a longitudinal 

 slit, blackish, slightly pulverulent; teliospores ellipsoid or oblong, 

 27-34 by 42-58 M, slightly or not constricted at septum, usually 

 rounded at both ends; wall blackish when mature, uniformly 2.5- 

 3.5 n thick, occasionally slightly thicker above, coarsely and promi- 

 nently tuberculate; pedicel colorless, fragile, once length of spore 



Urediniospores in the telia rather common, broadly ellipsoid or 

 obovoid, 27-35 by 32-42 ^u; wall golden- or cinnamon-brown, 

 about 1 .5 M thick, finely and moderately verrucose-echinulate, 

 the pores 12-15, scattered. 



On Dipterostemon pauciflorus (Torr.) Rydb. (Brodiaea capitata 

 pauciflora Torr., Dichelostemma pauciflorum Standley), Tumamoc 

 Hill, on grounds of the Desert Botanical Laboratory of the 

 Carnegie Institution of Washington, Tucson, Arizona, altitude 

 2,700 feet, February 25, III, 5800, February 26, O, I, III, 5801 type, 

 February 26, O, I, 5802, all by J. C. Arthur and F. D. Fromme; 

 also March 12, III, by W. A. Cannon. The collections were made 

 at different spots on Tumamoc Hill in vicinity of the Laboratory, 

 and in the year 191 4. 



A part of 5802 was used for a culture made at the protected 

 south side of the Laboratory building in the open, the resulting 

 infection being watched and the matured sori transmitted by 

 Dr. W. A. Cannon of the Laboratory staff. This culture is re- 

 ported in Mycologia (7: 85. March, 191 5), under the name 

 Puccinia nodosa. A water culture was made of the urediniospores, 

 which showed that they were capable of germination. Some 

 aberration was observed in their behavior, but the stay at the 

 Laboratory was too brief to obtain exact data, or to decide upon 

 their significance. The urediniospores in a number of collections, 

 kindly sent to Lafayette, Indiana, by Dr. Cannon, could not be 

 made to germinate. The behavior of urediniospores has never 



