484 PROCEEDINGS OF THE AMERICAN ACADEMY. 



but the barbules upon the lower half tipped ^Yith deep purple or violet : 

 achenes 1 .8 mm. long, upwardly hispid ou the angles. — Collected by 

 E. W. Nelson on the Sierra Madre, State of Chihuahua, Mexico, 29 

 September, 1899, no. 6499. Type in herb. Gray and herb. U. S. Nat. 

 Museum. Related to E. ageratifoUum, DC, and E. occidentale, Hook. 



Eupatorium prionophyllura. Tree ; appearing glabrous to the 

 unassisted vision, but covered upon the branchlets, petioles, veins of the 

 leaves, and pedicels by traces of a short close fuscous tomentum ; 

 branches curved ; cortex gray : leaves opposite, slender-petioled, broadly 

 ovate, conspicuously acuminate, usually obtuse at the base, incisely and 

 often somewhat doubly serrate-dentate nearly from the base to the apex, 

 thin, green on both surfaces, pinnately veined, 7.5 to 9 cm. long, two- 

 thirds as broad ; the teeth acuminate, incurved ; petioles 1 to 4 cm. long : 

 heads 2o-30-flowered, in terminal opposite-branched rounded at first 

 thyrsoid at length more open panicles ; bractlets filiform ; scales of the 

 involucre imbricated in about 3 series, the outer short and ovate, 

 acute, mucronate with a glandular tip, the inner oblong, obtusish, all 

 striate, fimbriate-ciliolate, externally stramineous becoming purplish or 

 fuscous in age especially near the tip, silvery and lucid within : corolla 

 glabrous, gradually narrowed from the summit to the base : pappus 

 white, barbellate, moderately copious, nearly equalling the corolla : 

 achenes at maturity dark brown, glabrous, lucid. — E. ixiocladon^ Klatt, 

 Bull. Soc. Bot. Belg. xxxi. 190, not Benth. — Collected by Prof. H. 

 Pittier ou the banks of the river Poros, no. 1705 (type in herb. Gray) 

 and near the Rancho Flores, no. 1900, Costa Rica. This sjiecies has 

 no close affinity with E. ixiocladon, Benth., a plant well shown by Mr. 

 J. D. Smith's no. 7501. 



Eupatorium quadrangulare, DC. Prodr. v. 150 (1836). Of this, 

 E. thyrsoideam, Moc, notwithstanding its supposed terete stems, is cer- 

 tainly a synonym. Nothing beyond the younger branchlets of E. thyr- 

 soideum appears to be known, while even in the square-stemmed E 

 quadrangulare these younger branches are often subterete. 



Eupatorium viscidipes. Stem slender, terete, dark-purple, mi- 

 nutely glandular and very viscid ; bi'anches opposite, spreading, curved 

 upward : leaves opposite, deltoid-ovate, caudate-acuminate, crenate-serrate 

 in the middle, 3-uerved from the obtuse or subtruncate base, 2.2 to 3.5 cm. 

 long, 1.3 to 2.5 cm. broad, minutely puberulent above, slightly paler and 

 punctate beneath with translucent dots ; petioles 1.2 to 1.7 cm. long : heads 

 rather numerous, small, 6 mm. iu diameter, about 18-flowered, borne in 

 a large loose corymbose leafy-bracted panicle ; pedicels filiform, 3 to 



