EUPATORIUMS OF PERU. 49 



d. Leaves ovate or elliptical. 



Heads about 16-flo\vered; involucral scales obtuse; 



leaves rhombic-ovate, 3— 4. .5 cm. wide 31. E. helianthifolium. 



Heads 20-24-flowered ; involucral scales acute; leaves 



elliptical, at maturity about 1 dm. wide 32. E. vestitum. 



c. Leaves glabrous or merely atomiferous beneath. 



Heads in a divaricately branched pyramidal panicle; 

 leaves undulate-margined and with a delicate prominu- 



lent reticulation above 33. E. orgyaloides. 



Heads in broad terminal rounded corymbs; veinlets not 



prominulent on the upper surface of the serrate leaves. 



Involucral scales conspicuously arachnoid-cilia te; 



leaves dull above, 1.5-2.3 cm. wide 34. E. drepanoides. 



Involucral scales minutely and obscurely ciliolate; 



leaves lucid above, 3-6 cm. wide 35. E. coelocaule. 



b. Leaves narrowly lance-oblong to linear, sessile or on very 

 short petioles (1-4 mm. long) e. 

 e. Heads large, 1.4-2.5 cm. long. 



Involucral scales regularly graduated in 3-4 series; 

 heads 1.4-1.8 cm. long. 



Leaves linear, about 3 mm. wide 18. E. Gayanu m . 



Leaves lance-oblong, 8-15 mm. wide 19. E. Ballii. 



Involucral scales much imbricated, but the outer scarcely 



shorter; heads 2.5 cm. long 20. E. Cursonii. 



e. Heads 7-10(-12) mm. high /. 

 /. Heads mostly 30-40-flowered, in loosely fastigiate- 



branched panicle 36. E. amygdalinum. 



J. Heads 7-15-flowered, mostly in dense thyrsoid inflo- 

 rescence g. 

 g. Leaves linear or nearly so, 3-6 mm. wide. 



Leaves strongly deflexed, tardily glabrate and 

 smoothish (not conspicuously rugose-bullate) 

 above, entire (the margins strongly revolute) 



21. E. lavandulaefolium. 

 Leaves spreading, promptly glabrate and strongly 

 rugose-bullate above, appearing crenulate from 

 the depressed veins in the very revolute 



margins 22. E. chotense 



g. Leaves narrowly lance-oblong, 1-2 cm. wide in 

 the middle. 

 Shrubs 1-2 m. high; leaves thickish, of firm texture, 



chartaceous or coriaceous 23. E. Volk'ensii. 



Herbaceous or nearly so, 2-3 dm. high; leaves thin, 



membranaceous, of soft texture 37. E. Sprucei. 



b. Leaf-blade contracted below into a winged petiolar por- 

 tion, either cuneate or cordate-auriculate at its insertionon 

 the stem. 

 Heads 14-17-flowered; leaves entire, tomentulose beneath. 



38. E. pilluanense. 

 Heads about 20-flowered; leaves coarsely toothed or lobed, 



coarsely pubescent on the veins beneath 39. E. Commersonii. 



Heads 200-300-flowered. Here maybe sought 81. E. nemorosum. 



I. Leaves palmately 3-7-nerved from or somewhat above the 

 base, or subpinnately veined, but with one of the lower pairs 

 of veins considerably longer or thicker than the others h. 

 h. Heads 4-7-fiowered i. 



