442 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



Senecio atriapiculatus ; Senccio Cohimhiantis Greene, Pittonia, 3 r 

 170, 1898; not S. resedifolitis Coluinbicnsis Gray, 1886: Senecio 

 lug-ens Gray, Syn. Fl. i" : 388, in part [Bot. Cal. i: 413; Man. 

 R. M. 209] ; not Richards. 



Taller and shorter, more leaf}', and with more numerous heads 

 than in the arctic S. lugens Richards. On prairies and in river- 

 valleys, up to an altitude of 2500 m. 



Montana: Upper Sand Coulee, 1888, R. S. Williams^ S^o; 

 Spanish Basin, June 26, 1897, Rydberg d' Bcssey, 32^4.; Bridger 

 Mountains, June 11, 52^6% Bozeman, 1883, Scribner, i2ja. 



Senecio arachnoideus. 



A stout and rather leafy perennial, copiously arachnoid-floccose 

 when young, with a short caudex and a cluster of fibrous roots ; 

 stem simple, 3-4 dm. high, striate, in age shining; basal leaves 7— 

 15 cm. long, rather thick, with a winged petiole ; blade lanceolate or 

 oblanceolate, acute, irregularly sinuate-dentate ; stem-leaves lan- 

 ceolate, sessile and half clasping with more or less auricled bases, 

 the margins sinuate-dentate and usually considerably wrinkled or 

 crisped ; heads in a dense corymbiform cyme, campanulate, 8—12 mm. 

 high and 8-10 mm. broad; bracts linear, acute, thick, conspicuously 

 black-tipped, shorter than the disk, the calyculate ones small, sub- 

 ulate ; rays light yellow, 8 mm. long and 2 mm. wide ; achenes ob- 

 long-C3'lindric, glabrous, shining. 



Nearest related to the preceding, but principally distinguished by 

 the long arachnoid pubescence and the sinuately dentate and crisped 

 leaves. In wet places. 



Montana: Deer Lodge, 1891, Kclsey (type). 



Idaho : Wiessner Peak, 1892, Sandberg, MacDougal & Hcllei\ 

 6og. 



Oregon : Wilkes Expedition. 



* Senecio glaucescens. , 



Perennial, with a very short caudex and a cluster of fibrous roots ; 

 glabrous or at first slightly hairy and more or less glaucous ; stem 

 2—7 dm. high, striate, shining, often tinged with red ; basal leaves 

 and lower stem-leaves 5-10 cm. long, spatulate or oblanceolate 

 or even oval, callous, dentate or very rarely subentire, acute or 

 obtuse, with a distinct winged petiole, rather thick and often some- 

 what glaucous ; upper stem-leaves reduced, lanceolate and sessile ; 

 cyme corymbiform, rather contracted ; heads campanulate, about i 

 cm. high and 8-12 mm. broad; bracts linear-lanceolate, acute, with 

 conspicuous black tips, and about two-thirds as long as the disk ; 



