COMPOSITAE (COMPOSITE FAMILY) 529 



segments short, entire, or the lateral often 2-lobed; scapes nearly naked: 

 rays twice the length of the very hirsute involucre: achenes minutely hairy; 

 pappus hispid-scabrous, as long as the corolla of the disk. (E. flabellifolius 

 Rydb. Bull. Torr. Bot. Club 26: 545. 1899.) Colorado and Utah to Mon- 

 tana and Idaho. 



29a. Erigeron trifidus discoideus A. Nels. Rayless form of the species, 

 and sometimes glabrate. Same range. 



30. Erigeron pinnatisectus (Gray) A. Nels. 1. c. 26: 246. 1899. From 

 cinereous-hirsute to glabrate, somewhat tufted, the rather few stems mostly 

 erect, 1-2 dm. high: leaves petioled, the blade pinnately divided into 9-11 

 linear and entire or more or less cleft lobes: heads rather large (8-10 mm. high) 

 or in depauperate specimens small : the rays purple or violet-purple, numerous, 

 8-14 mm. long. E. compositus pinnatisectus. Mostly high alpine; in the 

 mountains of our range. 



31. Erigeron ramosus (Walt.) B. S. P. Prel. Cat. N. Y. 27. 1788. Annual, 

 with somewhat appressed pubescence; the stem erect, 3-6 dm. high, corym- 

 bosely branched : stem leaves linear-oblong or linear-lanceolate, most of them 

 entire; basal and lowest cauline spatulate or oblong, usually serrate: bracts of 

 the involucre glabrous or nearly so: pappus double; the inner a series of slen- 

 der, fragile, deciduous bristles (often wanting in the ray-flowers) ; the outer a 

 persistent series of short, partly united, slender scales: rays white, rarely 

 purplish, occasionally minute or wanting. E. strigosus. E. annuus L. is 

 quite similar but taller and with more spreading pubescence and smaller 

 heads. Neither are indigenous to our range, but the former occurs in many 

 fields and the latter will no doubt be found sooner or later. Both are known 

 as DAISY FLEABANE. 



32. Erigeron divergens T. & G. Fl. 2: 175. 1841. Stems several or nu- 

 merous, ascending, from a stout taproot, sometimes decumbent at base; her- 

 bage roughened with a short hispid pubescence: leaves linear, 1-2 cm. long, 

 or the lower somewhat longer and linear-spatulate, the uppermost reduced: 

 heads solitary, terminating slender peduncles: rays numerous, filiform, 6 mm. 

 long, violet or purplish [or white (?)]: inner pappus of scanty slender bristles, 

 the outer of much shorter subulate squamellae. From Texas to Montana 

 and west to the Pacific. 



32a. Erigeron divergens arenarius (Greene) A. Nels. Freely, slenderly, 

 and diffusely branched: leaves small and numerous: rays pale (lavender): 

 the pappus apparently simple. (E. arenarius Greene, Bull. Torr. Bot. Club 

 25: 121. 1898.) Through the southern part of our range to Arizona. 



326. Erigeron divergens nudiflorus (Buckley) A. Nels. Branches rather 

 few and suberect, densely leafy for two thirds of their length and terminating 

 in a rather stout naked peduncle: leaves linear-spatulate, densely cinereous- 

 hirsute. (E. nudiflorus Buckley, Proc. Acad. Sci. Phila. 456. 1862; E. 

 pedunculata Heller.) Colorado to Arizona. The varieties as well as the 

 species are probably biennial. Intermediate forms are common. 



33. Erigeron colo-mexicanus A. Nels. Stems few to several from a slender 

 annual taproot, ascending, naked-pedunculiform above the middle, very 

 leafy, flowering when very short, the later heads on stems 7-15 cm. long: 

 leaves mostly linear-spatulate to linear, the basal sometimes oblanceolate 

 and 3-lobed at apex, all softly cinereous-pubescent: heads much as in E. 

 divergens. (E. cinereus Gray, PI. Fendl. 68. 1848; not E. cinereus H. & A. 

 Comp. Bot. Mag. 2: 50. 1836.) Southern Colorado and New Mexico. 



34. Erigeron flagellaris Gray, Mem. Am. Acad. 4: 68. 1849. More or less 

 cinereous with appressed pubescence; stems slender, diffusely decumbent and 

 flagelliform but leafy, some prostrate, some at length rooting at the apex and 

 proliferous: leaves small, entire; radical spatulate and petioled; those of the 

 branches becoming linear: solitary peduncles 4-10 cm. long: rays white or 

 purplish: pappus double, the outer of subulate bristles. (E. MacDougallii 

 Heller, Bull. Torr. Bot. Club 26: 599. 1899.) Moist soil; from Montana to 

 New Mexico and Texas. 



35. Erigeron philadelphicus L. Sp. PI. 863. 1753. Perennial by stolons 



ROCKY MT. BOT. 34 



