484 PROCEEDINGS OF THE AMERICAN ACADEMY. 
but the barbules upon the lower half tipped with deep purple or violet : 
achenes 1.8 mm. long, upwardly hispid on 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 Z. ageratifolium, DC., and E. occidentale, Hook. 
Eupatorium prionophyllum. 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 25-30-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. — Z. ixiocladon, Klatt, 
Bull. Soc. Bot. Belg. xxxi. 190, not Benth. — Collected by Prof. H. 
Pittier on the banks of the river Poros, no. 1705 (type in herb. Gray) 
and near the Rancho Flores, no. 1900, Costa Rica. This species has 
no close affinity with Z. ixiocladon, Benth., a plant well shown by Mr. 
J. D. Smith’s no. 7501. y 
EvuPATORIUM QUADRANGULARE, DC. Prodr. vy. 150 (1836). Of this, 
E. thyrsoideum, Moc., notwithstanding its supposed terete stems, is cer 
tainly asynonym. Nothing beyond the younger branchlets of 2. thy” 
sotdeum appears to be known, while even in the square-stemmed E 
quadrangulare these younger branches are often subterete. j 
Eupatorium viscidipes. Stem slender, terete, dark-purple, ™ 
nutely glandular and very viscid; branches opposite, spreading, curv 
upward: leaves opposite, deltoid-ovate, caudate-acuminate, crenate-serraté 
in the middle, 3-nerved from the obtuse or subtruncate base, 2.2 to 3.5 cm. 
long, 1.3 to 2.5 em. broad, minutely puberulent above, slightly paler and 
punctate beneath with translucent dots; petioles 1.2 to 1.7 cm. long: he 245 
rather numerous, small, 6 mm. in diameter, about 18-flowered, borne ™ 
a large loose corymbose leafy-bracted panicle; pedicels filiform, 3 to 
