EUPATORIUMS OF PERU. 



51 



h. Heads 14-30-flowered I. 



I. Perennial herbs or shrubs m. 



m. Leaves rhombic-ovate, attenuate to a subsessile 



base 47. E. inulaefoUum. 



m. Leaves ovate-lanceolate to suborbicular, obtuse, 

 rounded, or cordate at base. 

 Leaves pubescent or scabrous above. 



Middle and outer involucral scales acute. 



Heads rather few and loosely disposed in open 

 panicles ; pubescence of short light-colored hairs 

 neither gland-tipped nor conspicuoasly jointed. 



48. E. gracilentum. 

 Heads many, glomerate at ends of branches of 

 an open panicle, pubescence dense, dark, pur- 

 plish-brown, the hairs perceptibly dark-jointed. 49. E. Cookii. 

 Middle and outer involucral scales obtuse or 



rounded at the tip 56. E. inarrubiifolium. 



Leaves glabrous above, and merely puberulent on the 



nerves and veins beneath 50. E. marginatum. 



I. Delicate annual; leaves slender-petioled 5L E. microstemon. 



h. Heads 45-100-flowered. 

 Heads numerous, glomerate or at least crowded at the 

 ends of the branches in a leafy-bracted panicle ; pedicels 



mostly 0-3 mm. long 30. E. Lobbii. 



Heads numerous, in an open loose panicle; pedicels mostly 



1-2 cm. long; involucral scales multistriate .52. E. vitalbae. 



Heads in few (mostly l-5)-headed corymbs; pedicels 5-20 



mm. long; involucral scales 3-ribbed 16. E. tahonense. 



12. E. PERSiciFOLiUM HBK. Nov. Gen. et Spec. iv. 130 (1820); 

 Ball, Jour. Linn. Soc. xxii. 43 (1885); Robinson, Proc. Am. Acad. liv. 

 350 (1918). E. arborcum HBK. 1. c. 131; Robinson 1. c. 351. E. 

 compactwn Benth. Bot. Sulph. 112 (1844). — Lima: Huamantango, 

 Barclay (K., phot. Gr.); Obrajillo, Wilkes Exp. (Gr.); Chicla, Ball, 

 ace. to Ball, 1. c. Ancachs: Prov. Cajatambo: on grassy plains with 

 numerous scattered bushes, alt. 3400-3700 m., Ocros, 28 March, 1903, 

 Wcberbaucr, no. 2682 (Berl., fragm. Gr.). Cuzco: Ollantaytambo, alt. 

 3000 m., Cook & Gilbert, nos. 330 (U. S.), 335 (U. S.); Pifiasniocj, 

 Panticalla Pass, alt. 3600 m., Cook & Gilbert, no. 1809 (U. S.). 



In a recent paper the writer, 1. c, endeavored to maintain E. arboreum 

 HBK. as distinct from E. persiei folium, but the characters are so slight 

 that it now seems impossible to keep these species satisfactorily apart 

 or key them from each other with any clearness whatever. [Ecuad.] 



13. E. BUDDLEAEFOLiuM Benth. PI. Hartw. 135 (1844); Robinson, 

 Proc. Am. Acad. liv. 350 (1918). — Amazonas: Prov. Chachapoyas, 

 Matheics (Gr.). [Ecuad.] 



14. E. DISCOLOR DC. Shrubby; branches flexuous, slender, hex- 

 agonal, nearly smooth; leaves opposite, oblong-lanceolate, acuminate, 



