214 POLYGONACEAE 



Undershrubs, leafy only at the base; inflorescence longer than the stem. 

 Involucres vHlous-tomentose; leaf-blades equally white on both sides. 

 Leaf-blades narrowly oblanceolate ; branches of the inflorescence strongly 



ascending. 59. E. orendense. 



Leaf-blades broadly spatulate; branches of the inflorescence more 



spreading. 60. E. lagopus. 



Involucres glabrate; leaves usually less tomentose above. 



Leaf-blades oblanceolate or broadly oblong, not strongly re volute. 

 Involucres strongly angled, all sessile. 61. E. Thompsonae. 



Involucres not strongly angled; those of the forks peduncled. 



62. E. campanulatum. 

 Leaf-blades linear or narrowly linear-oblanceolate, usually with revolute 



margins. 



Involucres in the forks peduncled. 63. E. brevicaule. 



Involucres all sessile. 64. E. micranthum. 



Plants depressed, less than 1 dm. high, with heath-like leaves. 



65. E. contortum. 

 Perianth white or rose-colored. 



Suffruticose plants, leafy only at the base; inflorescence longer than the stem. 

 Involucres tomentose, all sessile. 66. E. spathulatum. 



Involucres glabrous, at least in age. 

 Leaf-blades spatulate or elliptic. 



Pedicels of the lower forks scarcely longer than the involucres; lobes 

 of the latter as broad as long ; perianth 3 mm. long. 



67. E. spathuliformc. 

 Pedicels of the lower forks several times as long as the involucres ; lobes 



of the latter longer than broad; perianth 2 mm. long. 



68. E. Ostlundi. 

 Leaf-blades narrowly oblanceolate to linear. 



Involucres all sessile. 



Leaves mostly flat; involucres narrowly turbinate; perianth 2-2.5 



mm. long. 69. E. lonchophyllum. 



Leaves mostly revolute; involucres campanulate; perianth 3-3.5 



mm. long. 70. E. nudicaule. 



Involucres in the forks of the inflorescence, at least the lower, distinctly 



peduncled. 

 Involucres broadly campanulate, about as wide as long. 



71. E. scoparium. 

 Involucres turbinate, decidedly longer than broad. 



Branches of the inflorescence almost erect. 



72. E. grangerense. 

 Branches of the inflorescence ascending-spreading. 



Leaf-blades narrowly linear-oblanceolate or linear, usually 



revolute. 73. E. tristichurn. 



Leaf-blades spatulate to oblanceolate, flat. 



74. E. salicinum. 



Shrubby plants, with the leafy stem usually longer than the inflorescence. 

 Leaves not revolute or scarcely so, distinctly petioled. 



Leaf-blades relatively broad, oblong to rounded-oval or obovate, obtuse. 

 Involucres 4-5 mm. long. 75. E. Fendlerianum. 



Involucres 2-3 mm. long. 



Branches of the inflorescence divaricate. 76. E. divergens. 

 Branches of the inflorescence ascending. 



Leaf-blades rounded or subcordate at the base, decidedly crisp. 



77. E. Jonesii. 

 Leaf-blades acutish at the base, not crisp, except sometimes the 



margins. 

 Inflorescence and stem loosely floccose, in age inclined to 



become glabrate. 78. E. corymbosum. 



Inflorescence and stem permanently and densely white- 



tomentose. 79. E. salinum. 



Leaf-blades narrow, spatulate to linear, mostly acute at the apex. 



Inflorescence many times compound, copiously branched; internodes 



long. 

 Inflorescence tomentulose, broom-like, with strongly ascending 



branches; involucres about 1.5 mm. long. 80. E. effusum. 

 Inflorescence glabrous, lax and with spreading branches; involucres 



2-2.5 mm. long. 74. E. salicinum. 



Inflorescence less compound; branches and internodes short, mostly 



spreading. 

 Involucres in the forks peduncled; peduncles slightly floccose. 



81. E. microthecum. 

 Involucres all sessile; peduncles densely white-tomentose. 



82. E. nebraskense. 

 Leaves linear or linear-oblanceolate, strongly revolute, subsessile. 



Peduncles not thickened upwards. 



Leaves glabrous or loosely floccose above. 



Stem 1-4 dm. high; leaves floccose above. 83. E. Simpsoni. 

 Stem less than 1 dm. high; leaves glabrous above. 



84. E. Alearnsii. 



