STANDLEY TREES AND SHRUBS OF MEXICO 1451 



41. Eupatorium dryophilum Robinson, Proc. Amer. Acad. 36: 478. 1901. 

 Eupaiorium adenospermum var. pleianthum A. Gray, Proc. Amer. Acad. 15: 



26. 1879. 



Eupaiorium pleianthum Robinson, Proc. Amer. Acad. 36: 483. 1901. 



Jalisco; type locality, "rocky hills near Guadalajara." 



Erect perennial, about 60 cm. high, slightly lignescent toward the base, with 

 habit and inflorescence as in the preceding; leaves opposite or subopposite 

 (except a few of the uppermost), subsessile, oval to ovate, rounded to acute at 

 tip, serrate, of firm texture, 1.5 to 4.5 cm. long, two-thirds as wide; heads 1.5 

 cm. high; phyllaries several-seriate, ovate-oblong, rounded at tip, usually purple- 

 tinged; achenes slender, glandular-atomiferous. 



42. Eupatorium monanthum Schultz Bip. in Seem. Bot. Vov. Herald 299. 

 1856. 



Colima, Guerrero, and Oaxaca, at 150 to 700 meters; type from the "Sierra 

 Madre." 



A straggling, alternately branched shrub; stems terete, mottled, pithy, scarcely 

 lignescent; leaves alternate, slender-petioled, suborbicular-ovate, obtuse to more 

 often shortly acuminate, entire to serrulate, mostly 3 to 8 cm. long and 2.5 to 7 

 cm. wide; heads 1 or 2-flowered, in paniculately disposed spherical glomerules, 

 sessile. "Zacate minero." 



Popularly believed to be an indicator of mineral deposits (Langlasse). 



43. Eupatorium pelotrophum Robinson, Proc. Amer. Acad. 42: 44. 1906. 

 Known only from the original collection, secured in clayey soil on the Sierra 



Madre, near the boundary of MichoacAn and Guerrero, altitude 2,300 meters. 



Shrub 1.5 meters high; branches virgate, slender, terete, dark brown, puberu- 

 lent; leaves opposite, ovate, caudate-acuminate, serrate at the sides, rounded at 

 base, 3 or 5-nerved from the base, 7 to 10 cm. long, 2 to 4 cm. wide, of firm texture, 

 sparingly puberulent and openly reticulate-veiny on both surfaces; petiole about 

 1 cm. long; heads commonly 4-flowered, in short axillary nodding cymes at length 

 forming subglobose glomerules about the upper nodes; phyllaries about 9, lance- 

 oblong, obtuse, purplish brown, scarcely half as long as the florets; coroUas white. 



44. Eupatorium campechense Robinson, Proc. Amer. Acad. 43: 30. 1907. 

 Campeche; tj'pe from Apazoli near Yohaltun. 



Shrubby, nearly glabrous; branches slender, terete, striate, smooth; leaves 

 opposite, petiolate, lanceolate, attenuate, often falcate, 3-nerved, thickish, shining, 

 8 to 10 cm. long, 2.4 to 3 cm. wide, rather distantly serrate-toothed, glabrous or 

 nearly so; petiole about 1 cm. long; heads about 5-flowered, slender-pediceled, in 

 fiattish corymbs; phyllaries stramineous, smooth, striate, obtuse, somewhat 

 5-ranked vertically; corollas pale, tubulate; achenes pubescent, 



45. Eupatorium leucocephalum Benth. PI. Hartw. 86. 1841. 



Veracruz, Puebla, Oaxaca, and Chiapas. Guatemala, where the type was col- 

 lected at Acatenango; also El Salvador. 



Suffruticose, 1 to 3 meters high, often slightly pubescent; stems terete; leaves 

 opposite, lance-oblong, long-acuminate, coarsely serrate, 3-nerved from near the 

 entire, obtuse or cuneate base, 6 to 10 cm. long, 2 to 3.5 cm. wide; petiole 1 to 3 cm. 

 long; heads small, 6 to 8-flowered, slender-pediceled in large ovoid thyrses; phyl- 

 laries ovate to oblong, white, lustrous. "Flor de plata," "hierba de plata," 

 "coyontura" (El Salvador); "chilca," "chilco" (Guatemala). 

 45a. Eupatorium leucocephalum var. anodontum Robinson, Proc. Amer. 

 Acad. 51: 534. 1916. 



Known only from the type collection, secured at La Victoria, near the boundary 

 between Michoacdn and Guerrero. 



Leaves subentire, somewhat narrower than in the typical form. 



