Jan. 1904] Cultures of Uredineae t?i 1903. 19 



8. Aecidium hydnoideum B". & C. Coming upon some 

 bushes of Dirca palustris L., the middle ot June, that were con- 

 spicuous with great numbers of yellow aecidial spots, search was 

 made for grass and sedge rusts in the vicinity. At one side, 

 l>\ a small ravine, was found a most luxurient growth of uredo 

 upon Bromus ciliatus L., with last year's teleutospores on the 

 kad radical leaves. The most distant bush of rusted Dirca was 

 not over a hundred feet away. 



As soon as suitable potted plants of Bromus ciliatus could 

 be established in the greenhouse, aecidiospores from the Dirca 

 were sown. The first sowing came to naught, as the host plant 

 failed to grow well. A sowing on June 25 gave uredospores 

 in abundance on July 4. Teleutospores were first observed on 

 August 10, although they probably appeared somewhat earlier. 



The success of this trial removes another rust from that 

 limbo of grass forms passing under the name of Puccinia rubigo- 

 vera. We may characterize the species as follows, under the 

 name 



Puccinia hydnoidea (B. & C.) nom. nov. {Aecidium hydnoideum 

 B. & C.) 



0. Spermogonia amphigenous in small groups on large yellow spots, 

 inconspicuous, punqtiform. 



1. Aecidia hypophllous, usually circinating about the spermogonia; 

 peridia short, cylindrical, pale, margin slightly recurved, finely erose 

 or torn; aecidiospores globoid or oblong-globoid, 11-15 by 14-19 jj.; wall 

 yellowish, thin, 1 p, minutely and inconspicuously verrucose. 



II. Uredosori chiefly epiphyllous, oblong, early naked, pulveru- 

 lent, fuscous; uredospores globoid or obovate-globoid, 18-21 by 20-28 ft ; 

 wall brownish, thin, 1 p-, abundantly echinulate, pores 4 or more, scattered. 



III. Teleutosori chiefly hypophyllous and caulicolous, small and 

 numerous, oblong, covered by the epidermis; teleutospores linear-oblong, 

 13-18 by 30-50 /j., truncate or oblique above, obtuse or slightly narrowed 

 below, not constricted at the septum; wall smooth, light brown, thin, 

 1-1.5 fi, thickened at apex, 4-7 /*; pedicel very short, colored; paraphyses 

 none, or few. 



This species, undoubtedly, does not embrace all the Ameri- 

 can rusts on Bromus. It is, doubtless, the common form east of 

 the Rocky Mts. Probably the multicellular form, found in Wis- 

 consin and Minnesota, Puccinia tomipara Trek, is distinct, al- 

 though it has not yet been shown that such irregular multiplica- 

 tion of cells in the teleutospore is a permanent character. 



SUMMARY. 



The following is a complete list of successful cultures made 

 during the season of 1903. It is divided into the two series : spe- 

 cies previously reported by the writer or other investigators, and 

 species now reported for the first time. 



