72 



ROBINSON. 



J- 



Heads 20-40-flowered ; pubescence of the 



stem sparingly if at all gland-tipped. 

 Leaves crenate-dentate, more than two- 

 thirds as wide as long. 

 Leaves deltoid-ovate, acute, mostly 2-3 



cm. long 68. E. vallincola. 



Leaves suborbicular-ovate, acuminate, 



mostly 4-6 cm. long 69. E. articulatum. 



Leaves serrate, about half as wide as long. 



64. E. tambillense. 

 j. Heads 80-100-flowered; pubescence of stem 



gland-tipped and viscid 70. E. probum. 



Stems sparingly to densely puberulent k. 

 k. Heads paniculate; inflorescence usually ovoid 

 to pyramidal, the branches widely spreading I. 

 I. Heads subglomerate at the tips of the diver- 

 gent branches of the panicle ; leaves crenate ; 



crenatures 13-22 on each side. 49. E. Cookii. 



I. Heads loosely disposed in the panicle m. 



TO. Leaves nerved essentially from the base. 



Stem covered with a dark and dense 



gland-tipped puberulence; leaves cren- 



ate-serrate; teeth about ten on each side. 



7L E. choricephalcddes. 

 Stem covered with white or gray incurved 

 scarcely or not at all glandular puberu- 

 lence; leaves remotely cuspidate-dentate; 



teeth 4-6 on each side. . 72. E. flexile. 



TO. Leaves nerved from a point 5-10 mm. 

 above the base. 

 Petiole 8 mm. long; achenes glabrous; 

 leaves sharply serrate; teeth 11-19 on 



each side 72a. E. Domheyanum. 



Petiole 10-25 mm. long; achenes some- 

 what roughened between the ribs ; leaves 

 mucronate-serrate ; teeth 5-12 on each 



■ side 64. E. tambillense. 



k. Heads (tending to be crowded) in flattish or 



round-topped compound corymbs, or (when 



few) irregularly cymose on chiefly erect or 



ascending branches n. 



n. Leaves for the most part conspicuously 



unequal-sided at the base; internodes very 



long (10-14 cm. in length) 74. E. Sodiroi. 



n. Leaves essentially symmetrical at the base; 

 internodes usually 2-5 (rarely 8) cm. lorig o. 

 0. Leaves small, 1-1. 5 (-2) cm. long, typically 

 ovate, finely crenate-serrate ; teeth about 

 5-7 on each side; slender-stemmed copi- 

 ously branched shrub 75. E. scopulorum. 



0. Leaves (at least the mature cauline) 

 larger, 2-7 cm. long p. 

 p. Heads small, about 5 mm. high; leaves 

 very shallowly mucronulate-serrate ; 

 stems nearly smooth but slightly and 

 obscurely villous toward the summit; 

 the hairs very slender, short, mostly 

 straight, not glandular 73. E. Gilbertii. 



