214 POLYGONACEAE 



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

 Involucres villous-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 revolute 

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



. Involucres not strongly angled; those of the forks peduncled. 



-r ri.1 J 1. ^2. E, campanulatum. 



Leaf-blades Imear or narrowly Imear-oblanceolate, Tisually with revolute 



margins. 



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



Involucres all sessile. 64 E micranihum 



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



Perianth white or rose-colored. 



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

 Involucres tomentose, aU sessOe. 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. 



■D ^- 1 p*u , i- 1 , . ^^' E. spathuliforme. 



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



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



T . , , , , ^, , ,. 68. E. Ostlundi. 



Leaf-blades narrowly oblanceolate to hnear. 



Involucres all sessile. 



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



mm. long 69. E. lonchophullum. 



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. 



T 1 X ,,. ^ ^ ., ,. '71- E. scoparium. 



Involucres turbinate, decidedly longer than broad. 



Branches of the inflorescence almost erect, 



■D u i. XI- . ^ 72. J?, gr anger ense. 



Branches of the inflorescence ascending-spreading 



Leaf-blades narrowly linear-oblanceolate or linear^ usually 



T l^^?^^^^- . 73. E, tristichum. 



Leaf-blades spatulate to oblanceolate, flat. 



Qu«,w». 1 X ixi- ^1. , « 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, Jonesit, 



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; intemodes 



long. 



Inflorescence tomentulose, broom-like, with strongly ascending 



branches;involucresaboutl.5mm. 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 intemodes short?, mostly 



spreading. 



Involucres in the forks peduncled; peduncles slightly floccose. 



T I » ., , SI. E, microthecum. 



involucres ail sessile; peduncles densely white-tomentose. 



T ^^, « I- f ^^ , 82, E. nebraskense, 



Lea\ e^ linear or hnear-oblanceolate. strongly revolute, subsessile. 

 Pedimcles 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. Mearnsil, 



