TWO NEW SPECIES OF RUSTS 



William H, Long 



On a collecting trip at Takoma Park, Maryland, with Dr. G. 

 G. Hedgcock, a caeoma-like species of Peridermium was col- 

 lected on Pinus rigida Mill, which proved to be Peridermium 

 delicatulum Arth. & Kern. Later, in looking over the species 

 of Peridermium in the Pathological Collections of the United 

 States Department of Agriculture, hoping to find other collec- 

 tions of this rare species, the writer found a specimen on Pinus 

 virginiana Mill., which from its gross characters appeared to be 

 Peridermium delicatulum, but a microscopic examination showed 

 it to be an undescribed species. 



On a trip made during 191 1 through some of the forests of 

 Arizona and new Mexico, the writer while descending the Santa 

 Catalina Mountains found, on Coursetia glaiidulosa Gray, a rust 

 which on microscopic examination proved to be an undescribed 

 species intermediate in its generic position between Phragmo- 

 pyxis Dietel and CalUospora Arth. Technical descriptions of 

 these two fungi are given below. 



Tricella gen. nov. 



Cycle of development includes only pycnia and telia, the 

 former subcuticular, the latter subepidermal. Pycnia conoidal, 

 ostiolar filaments usually present ; telia erumpent, without paraph- 

 yses ; teliospores free, three-celled by transverse septa ; walls 

 laminate, the inner layer firm, colored, the outer layer gelatinous, 

 translucent, overlaid by cuticle, the pores 3 or 4 in each cell and 

 lateral, pedicel bulbous in the middle. 



This genus is intermediate in its characters between Phragmo- 

 pyxis and CalUospora, having the three-celled teliospores of 

 the former, and the same cycle of development as the latter. 



Tricella acuminata sp. nov. 



O. Pycnia epiphyllous in groups intermixed with the telia, 

 smooth, pale-brown, subcuticular, 70-75^ wide by 50-70/^1 high; 

 ostiolar filaments hyaline, 25-35 11 long. 



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