COLOMBIAN EUPATORIUMS. 283 



tlic nervrs and principal veins hcncatli, entire 

 from (he base nearlj- or (juite to the middle 



30. E. arcuans. 

 I. Leaves membranaceous, conspicuously 

 toothed from much below th(> middle ni. 

 Hi. Heads jjedicelled; leaves lar^e, 5-G.5 em. 



wide; petiole aI)out 4 cm. lon^- • • -31. E. Vargasianum. 

 III. Heads .sessile in {^lomerules /*. 



II. Hispid-pubescent; teeth of leaves 



rounded 32. E. smilacinum. 



n. Pubescence, wdien present fine and soft o. 

 0. Leaves suborbicular-ovate, 5-8 cm. 



wide 33. E. acuminatum. 



0. Leaves lance-ovate, 2— i cm. wide 



34. E. p.seudoglomeratum. 

 k. Leaves rhombic-ovate or -lanceolate, cuneately 

 decurrent on short petioles or narrowed to a 



subsessile base 35. E. inulaefolium. 



f. Heads in dense ovoid or pyramidal panicles or 

 thyrses p. 

 p. Petioles at least 1 cm. long q. 



q. Leaves coarselj^ serrate-dentate; teeth 2-3 mm. 



high; petioles 2-A cm. long 36. E. morifolium. 



q. Leaves finely serrate; teeth 0.5-0.8 mm. high; 



petioles 1-1.5 cm. long 37. E. thyrsigerum. 



p. Leaves sessile or nearly so 38. E. densum. 



b. Heads numerously (20- cc) flowered r. 



r. Leaves 3 (-7) -nerved from or somewhat above the base s. 

 s. Involucral scales 2-3 (-5)-ribbed ; heads 3-8 mm. high t. 



t. Leaves lanceolate, small (2-5 mm. wide) 39. E. miserum. 



t. Leaves ovate (or in the glandular-pubescent E. pere- 

 zioides ovate-elliDtical), 1 cm. or more wide u. 

 u. Weak annual; heads numerous, small (4 mm. 

 high), separate on filiform pedicels in an open 



panicle 40. E. microstemon. 



u. Perennial herbs or shrubs, never viscid; heads 

 clustered in terminal corymbs or small usually 

 dense cymes, these separate and disposed in a 

 convex corymb v. 

 V. Heads about 25-flowered w. 



w. Heads 3.5-5.5 mm. high, in rather dense 

 terminal glomerules x. 

 X. Florets rose-colored or purplish; achenes 

 hispid at least on the angles; perennial 



herb 41. E. pycnocephalum. 



X. Florets white; achenes glabrous; rusty- 

 pubescent herb or shrub 42. E. Klattianum. 



w. Heads about 7 mm. liigh, in somewhat looser 



cymes; florets white 43. E. Pennellii. 



V. Heads 35-70-flowered, 7-8 mm. high; florets 

 roseate or lilac; leaves ovate-lanceolate, dull, 



punctate, drying dark 44. E. obscurifolium. 



u. Perennial herb; heads rather few in a lax diffuse 



panicle; pedicels 1-2 cm. long 45. E. perezioides. 



u. Perennial herb or shrub, smoothish, viscid about 

 the nodes and petioles; leaves slightly succulent, 



