FLOWERING PLANTS AND FERNS OF ARIZONA 925 



23. Leaves linear to narrowly oblanceolate, entire or, if a few of 

 the lowest ones rarely few-toothed, then the stems not 

 at all glandular-puberulous 2 I . 

 24. Plant definitely perennial; herbage hispid or coarsely 



hirsute 9. E. concinnus. 



24. Plant annual or biennial ; herbage puberulous or pilosulous. 



23. E. divergent. 



19. Stem pubescent with appressed or incurved hairs, rarely nearly or 



quite glabrous (25). 



25. Plant (the first flowering stems) scapiform, eventually producing 



long spreading small-leaved usually sterile runners from the 



base or the lower axils 20. E. flagellaris. 



25. Plant without long spreading runners (26). 



26. Leaves densely cinereous- or canescent-strigose, sometimes (in 



E. utahensis) only sparsely so (27). 



27. Stems scapiform, naked except toward the base, 8 cm. high or 



lower, 1-headed; plant densely cespitose, often forming 



large mats; achenes 2-nerved, compressed, pilose-ciliate on 



the margin, glabrous on the sides 16. E. compactus. 



27. Stems leafy at least to above the middle (28). 



28. Achenes essentially glabrous, subterete, 8- to 10-nerved; 



plant 12 to 20 cm. high 14. E. canus. 



28. Achenes pubescent, subquadrangular, 4-nerved; plant 



usually 30 cm. high or more 15. E. utahex>i>. 



26. Leaves not densely strigose, but sometimes cinereous-pubescent 



with incurved hairs (29). 



29. Stems glabrous, striate-angled, tall (about 60 cm. high), 



simple below the cymose heads; leaves linear or narrowly 



linear-oblanceolate, callous-pointed, hispidulous-ciliate, 



otherwise nearly glabrous 18. E. oxyphyllt-s. 



29. Stems more or less densely pubescent, or else the plants low, 

 not more than 25 cm. high, and the stems 1-headed (30). 

 30. Plant annual, single-stemmed; stem rather densely in- 

 curved- puberulous 22. E. BELLIDIASTRUM. 



30. Plants perennial, more or less densely cespitose (31). 



31, Involucre glabrous; basal leaves linear-spatulate to 

 obovate, some of them usually 3-toothed to pinnatifid, 

 the stem leaves much narrower, linear, entire. 



12. E. prixglei. 

 31 . Involucre more orless glandular (sometimes very minutely 

 so) and often also pilose or hirsute; leaves all entire 

 (32). 

 32. Plant entirely glabrous except for the very finely gland- 

 ular involucre and apex of the peduncles; leaves 1- 



nerved 10. E. perglaber. 



32. Plant more or less strigose-pubescent on the stems and 

 leaves; lowest leaves usually 3-nerved (33). 

 33. Rays purple; basal leaves essentially glabrous except 

 on the margin; peduncles glandular and spread- 



ing-pilose toward the apex 13. E. trsixfs. 



33. Rays white or purplish-tinged; basal leaves strigose 

 on the faces; peduncles strigose__ 17. E. eatoni. 



1. Erigeron simplex Greene, Fl. Francisc. 387. 1897. 



Alpine meadows, San Franciseo Peaks, 12,000 feet (Little 4656, 4709. 

 4733, 4777), August and September. Montana to northern New 

 Mexico, northern Arizona, and California. 



Some of the material from Arizona is rayless or essentially so, but 

 this feature is not constant even in the same colony. 



2. Erigeron macranthus Nutt,, Amer. Phil. Soc. Trans, ser. 2, 7: 



310. 1840. 

 Carrizo Mountains and Ryan Ranch (Apache County), near Flag- 

 staff (Coconino County), about 7,000 feet, oak thickets, etc.. July to 



