1450 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM 



long and 11 cm. wide; petiole 7 to 10 cm. long; con'mbs trichotomou.s, convex, 

 moderately den.se; heads about 16-flowered; phyllaries thin, not conspicuously 

 nerved, pale green, the inner oblong, obtuse, the outer much shorter, lanceolate, 

 acute; corollas trumpet-shaped, gradually expanded upward, purple but in old 

 specimens turning yellow, exceeding the white pappus. 



37. Eupatorium oresbioides Robinson, Proc. Amer. Acad. 44: 618. 1909. 

 Oaxaca; type from 'Alturas de Oaxaca, 1,800 m." Guatemala. 



Shrub, resembling the preceding but with leaves somewhat smaller (8 to 11 

 cm. long) and mostly hastately angled on one or both sides; petioles 1.5 to 5 cm. 

 long; corymbs much rounded, oblate-spherical; phyllaries and corollas purple- 

 tinged. 



38. Eupatorium hylobium Robinson, Proc. Bost. Soc. Nat. Hist. 31: 249. 

 1904. 



Known only from the original collection, secured in mountain woods between 

 San Martin and Ococingo, Chiapas. 



Shrub with terete flexuous branches at length roughened l)y prominent 

 lenticels; leaves rhombic-ovate, sharply serrate, thin, membranaceous, green and 

 glabrous above, slightly paler and puberulent on the veins beneath, 5 to 7 cm. 

 long, half as wide; corj^mbs leaf y-brac ted, round-topped, about 10 cm. in diam- 

 eter; pedicels filiform, flexuous, 3 to 6 mm. long; heads about 14-flowered, 

 7 mm. high; phyllaries pale green, thin, nearly nerveless, the inner oblong, 

 obtuse, the outer much shorter, lanceolate, attenuate; corollas gradually enlarged 

 upward, glabrous, the limb very short. 



39. Eupatorium pycnocephalum Less. Linnaea 6: 404. 1831. 

 Eupatorium diversifolium Schrad. Ind. Sem. Hort. Gotting. 1829: 2. 1829, 



without character. 



Eupatorium virgatum Schrad. Ind. Sem. Hort. Gotting. 1829: 2. 1829, with- 

 out character. 



Eupatorium schiedeanum Schrad. Ind. Sem. Hort. Gotting. 1832: 3. 1832. 



Eupatorium sonorae A. Graj^, PI. Wright. 2: 74. 1853. 



Conamon throughout Mexico. Widely distributed in the warmer parts of 

 continental America. 



A tropical weed 30 to 80 cm. high, for the most part wholly herbaceous but 

 occasionally developing distinctly lignescent stems; leaves opposite, petiolate, 

 deltoid-ovate, acuminate, crenate-serrate; heads about 25-flowered, 4 to 6 mm. 

 long, aggregate in small dense rounded corymbs, these often numerous and dis- 

 posed in ample leafy-bracted panicles; ph\llaries mostly elliptic-ovate, the middle 

 and inner rounded at tip, the outermost sometimes acute; corollas purple (rarely 

 white). "Mejorana" (El Salvador); "mejorana morada" (Guatemala). 



40. Eupatorium adenospermum Schultz Bip. in Seem. Bot. Voy. Herald 

 299. 1856. 



Type localit}'. Sierra Madre; subsequently collected only in the Sierra Madre 

 between Michoac^n and Guerrero. 



Shrub or perennial herb, erect, with slender, terete, virgate, brownish purple, 

 leafy stems; leaves alternate, subsessile, firm-chartaceous, ovate-oblong, acute, 

 subentire or serrulate, 4 to 7 cm. long, 2 to 3 cm. wide, reticulate-vein\^ on both 

 surfaces, puberulent on the chief veins beneath, sprinkled with sessile resinous 

 globules; corymbs fastigiately branched, flattish; heads about 15 mm. high, 

 about 10-flowered; phyllaries pluriseriate, ovate-oblong, rounded at tip; corollas 

 nearly tubular, white; style branches conspicuously clavate, yellow; achenes 

 slender, tapering at base, closely beset with globular glands. 



