200 NORTH AMERICAN FLORA [Voi^UME 7 



1 Podisoma Gymnosporangium Bon. Handb. Myk. 148. 1851. 



Podisoma tremelloides A. Br. Bot. Zeit. 25 : 94. 1867. 



Gymnosporangium tremelloides R. Hartig, IvChrb. Baumkr. 133. 1882. 



Puccinia juniperina Kutitze, Rev. Gen. 3^ : 507. 1898. 



Tremella penicillata Arth. Proc. Ind. Acad. Sci. 1900: 135. 1901. 



Roes te Ha fimbria ia Arth. Bull. Torrey Club 28 : 666. 1901. 



A ecidium fimbria turn Farl. Bibl. Index 1 : 44. 1905, 



Aecidium juniperinum Arth. Result. Sci. Congr. Bot. Vienne 343. 1906. 



Gymnosporangium penicillaium lyiro, Bidr. Finl. Nat. Folk 65 : 405. 1908. 



0. Pycnia epiphyllous, gregarious, in small groups 0.5-2 mm. across, on discolored 

 spots 2-7 mm. across, prominent, conspicuous, honey-yellow becoming blackish, hemi- 

 spherical, 140-160 /i in diameter by 75-90 ^ Wgh ; ostiolar filaments 45-65 ju long. 



1. Aecia bypophyllous, in annular or crowded groups 2-5 mm. across, on larger thick- 

 ened discolored spots 4-10 mm. across, at first cylindrical, 0.5-1.5 mm. high, 0.5-1 mm. in 

 diameter ; peridium soon becoming finely fimbriate to base, somewhat twisted or incurved ; 

 peridial cells usually seen only in side view, rhomboidal, very thick, 30-35 by 60-90 ju, some- 

 what hygroscopic, becoming very slightly curved when wet, the outer wall rather thin, 2-3 m, 

 smooth, the inner wall rather thick, 7-10^, rugose, the side walls very coarsely rugose with 

 thick, somewhat irregular ridges running from the inner side transversely and slightly down- 

 ward almost to the outer side with roundish or elongate ridge-like papillae interspersed ; 

 aeciospores globoid, very large, 28-35 by 30-45 ju ; wall chestnut-brown, thick, 3-5 m, rather 

 finely verrucose, the pores numerous, scattered, obscure. 



On Malaceae : 



Sorbui, occidenialis (S. Wats.) Greene, British Columbia. 



Sorbus scopulina Greene, Colorado, Montana, Washington, Wyoming ; British Columbia. 



Sorbus sitchensis Roem. , Wyoming ; British Columbia. 



III. Telia caulicolous, from a perennial mycelium, causing premature enlargement of 

 the branches, appearing on hemispherical swellings 1-4 cm. long breaking forth along the 

 sides of the larger branches, or on subglobose galls 1.5-2 cm. in diameter on the smaller 

 branches, applanate, indefinite, usually of considerable size, often covering the whole hyper- 

 trophied area, spreading out and becoming patelliform when fully mature, chocolate-brown 

 becoming yellowish and pulverulent by germination ; teliospores 2-celled, ellipsoid, 18-28 

 by 42-61 Mj usually slightly narrowed both above and below, slightly or not constricted at the 

 septum ; wall cinnamon -brown, uniform, 1-1.5 /x thick, the pores in the upper cell usvally 3, 

 1 apical and 2 near the septum, in the lower cell 2 near the septum ; pedicel cylindrical, 

 6-10 M in diameter, very long. 



On Juniperaceae : 



Juniperus sibirica Burgsd. {J. nana Willd. ), Colorado ; Alberta. 



Type locality: Sweden, on Juniperus {communis']. 



Distribution : Rocky Mountains from Alberta and British Columbia south to Colorado ; also 

 in Europe. 



Illustrations : Beitr. Krypt. Schweiz 2'^ : f. 277 ; Hedwigia 34 : Z, f. 1 ; Bot. Gaz. 49 : pi. 

 21,/. 8 ; E. & P. Nat. Pfl. li** : /. 33, C, /?, £; Forstl.-nat. Zeits. 4 : 384, /. 1-3, 14-17 ; Bull. N. 

 y. Bot. Gard. 7 : 457, /. 20; pL 155 J. 49. 



19. Gymnosporaagium gracilens (Peck) Kern & Bethel ; Kern, 



Bull. N. Y. Bot. Gard. 7 : 458. 1911. 



Aecidium gracilens Peck, Bot. Gaz. 4 : 128. 1879. 

 Gym. no sporangium, speciosum Peck, Bot. Gaz. 4 : 217. 1879. 

 Aecidium Rusbyi W. Gerard, Bull. Torrey Club 8 : 34. 1881. 

 Tremella speciosa Arth. Proc. Ind. Acad. Sci. 1900: 135. 1901. 



0. Pycnia epiphyllous, rather sparsely arranged in irregular groups 1-3 mm. across, 

 on discolored areas, honey-yellow becoming brownish, globoid, 145-150 /x in diameter ; osti- 

 olar filaments not prominent. 



1. Aecia bypophyllous, in small groups 2-5 mm. across, on discolored spots, cylindrical, 

 0.3-0.4 mm. in diameter by 2-3 mm. high ; peridium dehiscent at apex, retaining tubular 

 form, miargin rather deeply lacerate ; peridial cells seen in both face and side views, rhom- 

 boidal or linear-rhomboidal in side view, 31-39 by 71-98 ^i, broadly lanceolate in face view, 

 23-32 /x broad, moderately and densely verrucose over the entire surface vnth high slender, 

 and somewhat irregular papillae, the outer wall 3-4 ^ thick, the inner wall 10-15 ju thick ; 



