COMPOSITAE (COMPOSITE FAMILY) 583 



dense, corymbif orm ; heads 8-9 mm. high; bracts about 20, linear, acute, the 

 calyculate ones few, minute: rays dark orange, 4-7 mm. long, 3-4-nerved: 

 achenes angled, glabrous. (S. pyrrhochrous Greene, PL Baker. 3: 24. 1901: 

 S. Tracyi Rydb. 1. c. 33: 159.) Wyoming and Colorado. 



34. Senecio Balsamitae Muhl. Willd. Sp. PI. 1999. 1804. Light or yellowish- 

 green slender perennial, in age glabrate or slightly floccose at the base of the 

 leaves; stem 3-4 dm. high, striate, pale: basal leaves 3-8 cm. long, obovate or 

 broadly oval, generally tapering into the petioles, but sometimes truncate at 

 the base, obtuse, crenate or sinuate, light green; lower stem leaves oblanceolate 

 in outline and petioled; the upper lanceolate or linear in outline and sessile; all 

 deeply pinnatifid with narrow oblong or linear segments: cymes corymbif orm ; 

 heads 7-8 mm. high; bracts linear, acute; calyculate ones few, linear, small 

 and crisped: rays yellow, about 6 mm. long: achenes hispid-puberulent on the 

 angles. S. aureus Balsamitae. (S. flavidus Greene, Pitt. 4: 108. 1900; S. 



'rens and S. aurellus Rydb. 1. c. 181 & 182.) Across the continent; ours 

 thought by some to be distinct; if so, the name S. flavulus will stand. 



35. Senecio mutabilis Greene, 1. c. 113. Stems in a small dense tuft, erect 

 or ascending, 1-3 dm. high; pubescence varied, from tomentulose or loosely 

 floccose-hoary to almost or quite wanting: leaves obovate-spatulate to broadly 

 linear or lanceolate, nearly entire or serrate to sinuately or pectinately or 

 even somewhat lyrately pinnatifid, the apex often tridentate: heads few to 

 many, 8-10 mm. high, the involucres glabrous: rays mostly tridentate and 

 4-nefved, light yellow to nearly orange-color. S. aureus compactus. (S. com- 

 pactus Rydb. Mem. Torr. Bot. Club 5: 342. 1893, not S. compactus Kirk; S. 

 oblanceolatus and S. tridenticulatus Rydb. Bull. Torr. Bot. Club 27: 175 & 176. 

 1900; S. condensatus Rydb. Fl. Col., not S. condensatus Greene, which is a 

 plant of the Blue Mountains, Washington.) Wyoming to New Mexico and 

 Utah. 



36. Senecio discoideus (Hook.) Brit. 111. Fl. 3: 479. 1898. Perennial, 

 glabrous except for small tufts of wool in the axils of the lower leaves; stem 

 rather stout, 3-6 dm. tall: basal leaves oval to ovate, obtuse, thin, sharply 

 dentate, abruptly narrowed into petioles longer than the blade; stem leaves 

 few, small, more or less laciniate: heads few or several, slender-ped uncled, 

 corymbose; bracts of the involucre narrowly linear, 6-10 mm. long: rays 

 usually very short, or none. S. aureus discoideus. (S. fedifolius Rydb. 1. c. 

 183; S. nephrophyttu* Rydb. Mem. N. Y. Bot. Card. 1: 446. 1900.) Wet 

 places in the valleys in our range; across the continent northward. 



37. Senecio ereinophilus Rich. App. Frankl. Journ. 2: 31. 1823. Stems 

 freely branching, leafy up to the inflorescence: leaves mostly oblong in outline, 

 laciniatcly pinnatifid or pinnately parted, the lobes usually incised or acutely 

 dentate: heads numerous in corymbif orm cymes, 8-10 mm. high, short- 

 peduncled; involucre campanulate or narrower, minutely bracteolate; proper 

 bracts commonly purple-tipped: rays 7-9, 4-6 mm. long: achenes either 

 minutely papillose-cinereous or glabrous. (S. MacDougallii Heller, 1. c. 592.) 

 Extending southward through the Rocky Mountains (from British America) 

 to New Mexico and Arizona. 



38. Senecio filifolius Nutt. Trans. Am. Phil. Soc. 7: 414. 1841. More or 

 less permanently tomentose; stems suffruticose at base, much-branched, the 

 branches diffuse, very leafy to the summit: leaves pinnately 5-9-parted; the 

 segments very narrowly linear, entire, obtusish, often unequal, mostly with 

 revolute margins: heads (rather large) corymbose, on short peduncles, calycu- 

 late with a few small subulate scales: rays about 7, linear, somewhat elongated: 

 achenes strigose-canescent. In valleys; from Colorado and Utah to Arizona 

 and Texas. 



39. Senecio Riddellii T. & G. Fl. 2: 444. 1842. Glabrous throughout; stem 

 terete, very leafy, corymbose at the summit: cauline leaves pinnately 5-9- 

 ptiriod; the segments narrowly linear, obtuse, entire, flat, somewhat dilated 

 towards the apex (thickish and rather rigid): heads (large and showy) on 

 short peduncles, disposed in a compound corymb, calyculate with subulate 

 bracts: rays about 12, linear, elongated: achenes minutely puberulent. ($. 



