COMPOSITAE (composite FAMILY) 527 



sutely ciliate or sometimes nearly glabrous, no glandular roughness: involucre 

 more or less villous-pubescent, only 5-6 mm. high: rays mostly pale purple. 

 {E. Parryi Canby & Rose, Bot. Gaz; 15: 65. 1890; Ei Seribneri Canby, 1. c.; 

 E. vetensk Rydb. Bull. Torr. Bot. Club 32: 126. 1905.)— In the highest 

 mountains of our range and extending far northward. ' 



18. Erigeron ursinus Eat. Bot. Kin^s Exp. 1^8. 1871. Stems 1-2 dm. high, 

 loosely caespitose: leaves green, mostly smooth and glabrous, but their mar- 

 gins more or less hirsute-oiliate, spatulate to narrowly oblanceolate;;Cauline 

 ones lanceolate or linear and acute: involucre (6 mm. high) and naked summit 

 of .flowering stem hirsute-pubescent ^ rays 40 or 50, purple, narrowly linear, 

 6 mm. long. — Alpine and lower in our range and westward to California.; 



18a. Erigeron ursinus gracilis (Rydb.) A. Nels. More leafy and the whole 

 plant more or less sfctigosei^ubescent: \E. gracilis Rydb. Mem. N. Y. Bot. 

 Gard. 1: 401. 1900.)'-'-Subalpine in open grassy places; Yellowstone Park. 



19i Erigeron Engehnannii A. Nels. Bull. Torr. Bot. Club 26: 247. 1899. 

 Crown woody, from nearly simple to vnumerously but very short-branched : 

 leaves numerous, crowded on the crowns, linear, on very slender petioles 

 which about equal the blade, closely subcinereous, somewhat ciUolate on 

 the petioles, 2-6 cm. long (including the; petioles) : stems weak,- decumbent 

 or prostrate, moderately leafy, 3-6 cm. long, monocephalous or with 2 or 3 

 heads r peduncles short, ascending, 1 or mdre-braoted; heads rather small; 

 involucre about 5 mm.: high; the bracts equal, narrowly linear, acuminate, 

 dark green with light margins, ciliolate: rays white, broadly linear, 40 (more 

 oriJesS), the Idgules about 5 mm. long, equal (S. simulans Greene, PI. Baker. 

 3: 31. 1901).— ^tony slopes and foothills at middle elevations;- Wyoming, 

 Colorado, and Utah. 



20. Erigeron EatoniirGrayj Proc. Am. Acad. 16: 91. 1880* xiStems several 

 from the crown of -a strong taproot, slender and weak, diffuse; 1-2 dm. long, 

 simple or with 2 or 3 monocephalous branches: leaves all linear, thickish, 

 minutely pubescent ; the radical about 5 cm. long and the broadfest 4 'mm. wide : 

 heads only 6 mm. high; bracts of the sparsely hirsute involucre little unequal: 

 rays seldom over 20, at most 6 mm. long, white or purplish. (E. nematophyllus 

 Rydb. Bull. Torr. Bot. Club 32: 124. 1905.)— On the loWer slopes of the 

 mountains; Wyoming to Colorado and Utah. 



21. Erigeron- polioSpermus Gray, Syn. Fl. 1: 210. 1884. Oaudex multi- 

 cipital,;the branches-short and crowded; stems simple, numerous, rather closely 

 pubescenti with spreading unequal hairs, leafy belo^, niked-pedunculate above, 

 7-15 cm. long: leaves crowded on the crowns, short-hirsute all over, the mar- 

 gins strongly hirsute-cihate especially on the petioles, linear-spatulate, 3-5 

 cm. long i(iricluding petiole) ; stem leaves several, similar but becoming smaller 

 upward: peduncles naked or with a fiUform bract, monocephalous; heads 

 large, including ithe spreading rays 20-25 mm. broad; involucral bracts nar- 

 row, in 2 iowSj hirsute, long-acuminate, with a dark green midrib: rays 20- 

 50, purple or violet. (E. wyomingensis and E . inamoenus A. Nels. Bull. Torr. 

 Boti'CIub 26: 248. 1899.)^GraveUy hills; Wyoming to Montana and Oregon. 



22. Erigeron luteus A. Nels. 1. c. 27: 33. 1900. Densely tufted on a multi- 

 cipitalcaudex;; leaves Jclosely crowded on the crowns, all narrowly linear with 

 slightly I tapering, petiole-Uke base, subcinereous, 3-5 cm. long: stems mono- 

 cephalous, simple, scape-like but bearing 2 or more short leaves below, the pe- 

 duncular portion usually -with 1 small bract, from barely exceeding the leaves to 

 about twice as long: heads 6-8 mm. high; the -involucral bracts linear, acutish, 

 somewhat unequal and in 2 rows, ratheir shorter than the disk: rays 30-40^ a 

 pure yellow, rather broad and short, the Ugules only 3^ mm. long: pappus in 2 

 series, the outer of very short, inconspicuous bristleB;. the inner bristles rather 

 sparse and coarse, nearly as long as the tube of the disfecorollas; achenes 

 minutely pubescent. '{Chrysopsis hinteUa T)C. 5: 327. 1836; E. curvifolius 

 Piper, BuU. Torr. Bot. Club 27: 396.- 1900.)— Sandy stream banks; Yellow- 

 stone Park to the plains of the Columbia. 



23. Erigerdn microlonchus Greene, Pitt. 3: 293. 1898. Slenderly fusiform 

 perennial root bearing at the crown a central tuft of leaves encircled by several, 



