FLOWERING PLANTS AND FERNS OF ARIZONA 241 



21. Involucres turbinate-campanulate, distinctly peduncled, the 

 peduncles usually more than 1 mm. long; perianth white or 

 pink (22). 

 22. Outer lobes of the perianth obovate, truncate, often emargi- 

 nate at apex, narrowed at base: involucres glabrous exter- 

 nally: peduncles usually 5 mm. long or longer (23). 

 23. Peduncles more or less deflexed or decurved: involucres 

 often many- (more than 10-) flowered; outer lobes of 

 the perianth more or less panduriform; scapes usually 

 erect or ascending ._ 20. E. cerxuum. 



23. Peduncles spreading; involucres usually few- (about 5-) 



flowered: outer lobes of the perianth broadly flabelli- 



form: scapes spreading 21. E. rotundifolium. 



22. Outer lobes of the perianth ovate to nearly orbicular, rounded 

 at apex, more or less cordate at base (24). 



24. Involucres, peduncles, and bracts normally glandular- 



pubescent; scapes with divaricate branches; some of the 



peduncles 5 mm. long or longer 22. E. parryi. 



24. Involucres, peduncles, and bracts glabrous: scapes with 



ascending branches: peduncles seldom more than 3 



mm. long (25). 



25. Peduncles more or less deflexed: outer lobes of the 



perianth broadly ovate to suborbicular, scarcely 



longer than wide, cordate 23. E. deflexum. 



25. Peduncles erect or ascending: outer lobes of the perianth 

 oblong-ovate, distinctly longer than wide, subcordate. 



24. E. INSIGNE. 

 20. Peduncles filiform, often more than 10 mm. long (26). 



26. Glandular pubescence present on the involucres, peduncles, 

 and bracts; involucres hemispheric, glandular-puberulent out- 

 side, 2 to 2.5 mm. long, usually more than 10-flowered; 

 perianth white or pinkish, the outer lobes flabelliform and 

 somewhat cucullate, greatly dilated from the narrow claw; 

 scapes floccose below; peduncles often 20 mm. long. 



25. E. THURBERI. 



26. Glandular pubescence none or obscure: involucres turbinate, 



glabrous or nearly so outside, not more than 1.5 mm. long, 



few- (seldom more than 8-) flowered; outer lobes of the 



perianth not flabelliform or cucullate (27). 



27. Scapes 10 to 20 cm. long, diffusely branched with spreading 



branches, glabrous or nearly so, as are also the bracts; 



leaf blades glabrate above; perianth yellowish, fading 



pinkish, the outer lobes oblong, not constricted. 



26. E. WETHERILLII. 



27. Scapes usually 30 cm. long or longer, fewer branched, with 

 ascending branches, more or less villous or tomentose at 

 the nodes, as are also the lower bracts (28). 

 28. Plant biennial (?) ; basal portion of the scapes leafy and 

 with very short internodes: leaf blades sparsely ianate 

 to densely whitish tomentose on both faces, their mar- 

 gins often pronouncedly crispate; perianth yellowish, 

 sometimes fading pinkish, the outer lobes narrow, 



panduriform 27. E. capillars. 



28. Plant annual; scapes not leafy above the basal rosette: 

 leaf blades green and sericeous above, white-lanate 

 beneath; perianth whitish or pink (sometimes yellow- 

 ish?), the outer lobes oblong, not constricted. 



28. E. SUBRENIFORME. 



1. Plants perennial, the caudex, at least, thickened and woody (29). 

 29. Stems not, or not noticeably, woody above ground (30). 



30. Achenes conspicuously winged with membranous wings; stems tall, 

 stout, sparingly branched, leafy above the basal rosette; leaf blades 

 oblanceolate, tapering into long petioles; involucres not strongly 

 ribbed (31). 



