1434 COiS^TRIBUTIONS FROM THE NATIONAL HERBARIUM 



Leaves chartaceo-coriaceous, cuneate at base. 

 Inflorescence glabrous or obscurely puberulent. 



16. E. hospitale. 



Inflorescence tawnj'-velvety 17. E. daleoides. 



Heads shortly slender-pediceled; leaves drying green. 

 Leaves subentire, more than twice as long as wide. 



18. E. hebebotryum. 

 Leaves inciselj^ toothed, less than twice as long as wide. 



20. E. hemipteropodum. 



Veinlets raised on upper leaf surface 19. E. morifoliuni. 



Petiole winged, cordate-clasping at base 21. E. quadrangulare. 



Leaves palmate-nerved at or from near base. 

 Petiole winged to the cordate-clasping base. 



Stem square in section 21. E. quadrangulare» 



Stem subterete 22. E. thyrsoideum. 



Petiole (of cauline leaves) cuneate-winged from top to near middle. 



20. E. hemipteropodum* 

 Petiole not winged. 



Heads thistle-shaped; florets much exceeding the involucre. 



Heads 4 to 6 (to 7) mm. high; involucre turbinate; phyllaries 

 1-nerved. 

 Phyllaries linear to lance-linear, attenuate; leaves bright green, 

 sharply toothed; veins prominently netted between the 



nerves 23. E. ortegae. 



Phyllaries lanceolate to elliptic, obtuse to merely acutish; 

 leaves dull green, subentire; veins not conspicuously 



netted 24. E. haenkeanum. 



Heads 7 to 8 mm. high; involucre ovoid. 



Leaves lance-ovate, twice as long as wide, tomentellous be- 

 neath 25. E. mendezii. 



Leaves deltoid-ovate, less than twice as long as wide. 

 Phyllaries loosely imbricate, narrowly lanceolate, all acute. 



26. E. stillingiaefolium. 



Phyllaries closely imbricate, lance-oblong to rhombic-ovate. 



Phyllaries acute or acutish; pedicels puberulent to slightly 



villous 27. E. collinum. 



Phyllaries obtuse; pedicels stoutish and velvety. 



28. E. neaeanuiTi. 

 Heads not thistle-shaped. 



Heads subsolitary; pedicels 6 to 10 cm. long__29. E. longipes. 

 Heads clustered; pedicels rarely over 1 cm. long. 

 Phyllaries all acute. 

 Heads 3 to 6-flowered. 



Leaves ovate; inner phyllaries about 3 mm. long. 



30. E. palmeri. 

 Leaves lanceolate; inner phyllaries 4 to 5 mm. long. 



31. E. solidaginifolium. 

 Heads 10 to 40(to 60) -flowered. 



Petiole (if present) not above one-sixth length of blade. 

 Heads 7 to 8 mm. high; leaves glabrous but often gluti- 

 nous 32. E. collodes. 



Heads 10 to 15 mm. high; leaves pubescent beneath. 



Outer phyllaries ovate, acute 33. E. bigelovii. 



Outer phyllaries ovate-lanceolate, attenuate. 



34. E. turbinatum. 



