440 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



Senecio crassulus Gray, Proc. Am. Acad. 19 : 54 [Syn. Fl. i^ : 387 : 



Man. R. M. 208] . 



In wet soil, at an altitude of 1000-2000 m. 



Montana: Park Co., 1887, Tweedy, jjp; Gallatin Co., 1886, 

 Tweedy ; Bridger Mts., 1886, Flodman, Q14; Cedar Mountain, July 

 16, 1897, Rydberg & Bessey, s^49' 



Yellowstone Park: Pebble Bank, 1885, Tzveedy, yi^. 



Idaho : Mt. Chauvet, July 29, 1897, Rydberg & Bessey, s~4^ ^^d 

 5^50 (a monocephalous specimen). 



* Senecio semiplexicaulis. 



Stem 4-6 dm. high, glabrous; lower leaves obovate. tapering into 

 a winged petiole, acute, the upper oblong, more or less clasping by a 

 broad, sometimes slightly auricled, base, acute or often acuminate, all 

 very thin, sinuately dentate and often, especially the uppermost, with 

 salient teeth ; C3'me with rather few heads on long pedicels ; heads 

 12-15 mm. high, campanulate ; bracts oblong, tipped with black, 

 much shorter than the disk ; rays narrow, about 8 mm. long : achenes 

 glabrous, cylindric, striate, nearly equalling the pappus in length. 



This has been referred to S. //tgeus or some of its varieties, but has 

 very little relationship with it. The relationship is evidently with 

 S, crassulus, and it is doubtful if it should not rather be regarded as 

 a variety of that species. The involucral bracts, however, are not 

 very thick and fleshy and the leaves are not of a " firm texture"; 

 this is, without doubt, the reason why it has not been referred to S. 

 crassulus. In dry material they are even much more alike than in the 

 fresh state. In wet soil, at an altitude of 2000-3000 m. 



Yellowstone Park: East De Lacy's Creek, August 18, 1897, 

 Rydberg & Bessey, ^2^1 (type) ; 1884, Tzveedy, 118. 



Idaho : Teton Range, 1872, Coulter. 



Utah : Wasatch Mountains, 1879, M. E. Jones, iisj. 



* Senecio pereziifolius. 



Stem 6-8 dm. high, glabrous, striate, somewhat branched above; 

 basal leaves 2-2.5 d'^- ^o"g' very thin and glabrous, oblong or oval, 

 tapering into a winged petiole, sinuately dentate with small but sharp 

 salient teeth ; lower stem-leaves similar, but sessile, the upper ones 

 linear and with entire margins ; cyme rather narrow^ ; heads cylindric- 

 campanulate, about i cm. high; bracts linear, tipped with black, much 

 shorter than the disk ; rays fully i cm. long ; achenes brown, glabrous, 

 about two-thirds as long as the white pappus. 



Perhaps somewhat related to S. rapi/olius, but cannot be confused 



