FLOWERING PLANTS AND FERNS OF ARIZONA 243 



42. Leaf blades lanate-fomentose, mostly obovate or oblanceolate, 



obtuse 40. E. pulvixatu.m. 



41. Scapes 10 tc 30 cm. long (43). 



43. Scapes usually not branched: involucres sessile in a capitate 



inflorescence: perianth glabrous outside, pale yellow or 

 cream-colored, the outer lobes broadly obovate, truncate 

 or emarginate, subcordate at base; leaf blades oval to 



nearly orbicular 37. E. ovalifolium. 



43. Scapes sparingly dichotomous or trichotomous near the 

 summit; perianth densely white-villous outside, yellow, 

 the outer lobes ovate, obtuse; leaf blades lanceolate, 

 narrowly elliptic, or oblanceolate; plant silky- villous. 



38. E. LACHXOGYXUM. 



40. Plant not pulvinate: involucres numerous, all or nearly all of 

 them sessile; perianth glabrous outside (44). 

 44. Involucres glabrous or glabrate except on the margin, the teeth 

 obtuse or truncate (45). 

 45. Plant not scapose, the stems leafy up to the inflorescence, the 

 leaves mostly falling before anthesis: stems lanate, at least 

 below the inflorescence; inflorescence compound-cymose, 

 many-branched, the branches flexuous, the ultimate 

 branches divergent or even decurved; involucres about 

 2 mm. long, more or less ciliate; perianth white. 



41. E. PLUMATELLA. 



45. Plant scapose, the large leaves all or nearly ail basal, per- 



nstent; scapes glabrous except at the nodes; inflorescence 

 dichotomous or trichotomously forked, the branches few, 

 a-cending: involucres 3 to 3.5 mm. long, glabrous or 

 obscurely ciliolate; perianth yellow__42. E. thompsoxae. 

 44. Involucres lanate on most of their surface; stems lanate- 

 tomentose; perianth white or pink (46). 



46. Plant not scapose, the stems leafy up to the inflorescence; 



leaf blades lanceolate, elliptic, or oblanceolate, acute at 

 base, not more than 6 mm. wide, short-petioled; inflores- 

 cence simple or few-branched with the branches ascending 

 at a narrow angle, racemiform or with the involucres glom- 

 erate toward the ends of the branches.__43. E. wrightii. 

 46. Plant scapose or subscapose, the well-developed leaves all or 

 nearly all basal; leaf blades ovate or oblong-ovate, rounded, 

 subcordate, or occasionally cuneate at base, 10 mm. wide 

 or wider, long-petioled (47). 

 47. Inflorescence racemiform, elongate, simple or with very few 

 virgate branches; involucres 4 to 5 mm. long, not much 

 surpassing the large, strongly connate bracts. 



44. E. RACEMOSUM. 



47. Inflorescence compound-cymose, many-branched, the 



branches ascending at a wide angle, stout ; involucres not 



more than 2 mm. long, much surpassing the small, nearly 



distinct bracts 45. E. jonesii. 



29. Stems noticeably woody above ground: involucres mostly sessile or nearly 



so, or some of them often long-pedunculate in E. simpsoni (48). 



48. Perianth silky-villous, white or pink; cymes or their ultimate divisions 



dense, subcapitate; leaf blades pilose or villous above, lanate beneath, 



narrow, strongly re volute: leaves often fascicled: plant shrubby; 



involucres silky-villous, many-flowered 46. E. fasciculatum. 



48. Perianth glabrous; inflorescence rarely subcapitate: leaf blades lanate or 

 glabrate above (49). 

 49. Branches of the inflorescence rigid, divaricate, more or less spinescent, 

 scabrous or puberulent : low, intricately branched shrubs; stems 

 usually conspicuously white-lanate in the axils below the inflorescence, 

 the latter seldom conspicuously cymose; involucres few-flowered, 

 1 to 2 mm. long, turbinate, glabrous or glabrate, sessile, the teeth 

 very obtuse or truncate: leaves usually fugacious, the blades lanceo- 

 late or oblanceolate, the petioles short (50). 

 50. Branches of the inflorescence sharply quadrangular, deeply sulcate, 

 obscurely puberulent, not papillate 47. E. sulcatum. 



