ROBINSON. — SPERMATOPHYTES OF MEXICO. - 483 



tomeiitulose under a lens; heads numerous, crowded, small, about 10- 

 flowered, short-pedicelled ; scales of the involucre very few, unequal, 

 elliptical, rounded at the apex, glabrous but erose-ciliolate, in a dried 

 state brown : corolla glabrous or nearly so even at the limb, without 

 clearly marked throat, equalled by the white pappus : achenes (young) 

 pale, glabrous, 1.8 mm. long. — Collected by E'. W. Nelson near Piua- 

 bete, Chiapas, Mexico, 8 February, 189G, no. 3785. This species is 

 near but clearly distinct from E. daleoides, Hemsl. and E. tepicanum, 

 Hemsl. 



Eupatorium pleianthum. Doubtless perennial : stem slender, 

 terete, scabrous-puberulent, finely striate, reddish brown, loosely few- 

 branched above : leaves opposite, ovate, essentially sessile, thickish, 

 reticulate-veiny, coarsely few-toothed, acute, cordate, 3-nerved, 2.5 to 

 3.5 cm. long, two-thirds as broad, slightly scabrous upon both surfaces, 

 covered below by bright resinous globules : heads large, 2 cm. in diame- 

 ter, slender-pedicelled, erect ; involucral scales imbricated in 3 or 4 rows, 

 oval to oblong, rounded at the apex, thin, glabrous and glutinous, striate, 

 pale green, scarcely herbaceous : corollas 6 mm. long, gradually nar- 

 rowed from the summit to the base, about equalled by the copious stiffish 

 tawny pappus : styles very long and conspicuous, clavate ; achenes 5 to 

 6 mm. in length tapering toward the base, reddish brown, covered with 

 resinous globules, not tranversely striate. — E. adenospermnm, var. 

 pleianthian, Gray, Proc. Am. Acad. xv. 26. — Collected by Dr. Ber- 

 thold Seemann, \Yestern Mexico. Type in herb. Gray. While sharing 

 many characters with E. adenospermum, Sch. Bip., this plant differs so 

 markedly in its opposite (not alternate), shorter, ovate not oblong leaves 

 of differing dentation that intergradation seems very unlikely. 



Eupatorium prionobium. Branches ascending, terete, green, 

 striate, pul)erulent : leaves opposite, petiolate, deltoid, ovate to ovate- 

 oblong, cordate witli open sinus and hastate tendency, acutish to rounded 

 at the apex, crenate or crenate-serrate, thickish, bright green but covered 

 with short scattered white hairs upon both surfaces, scarcely paler be- 

 neath, 2 to 4 cm. long, 1.7 to 2.5 cm. broad ; petiole puberulent, 6 mm. 

 long, sulcate upon the upper side : heads small, about 20-flovvered, in 

 round-topped sessile cinereous-puberulent corymbs; pedicels 3 to 5 mm. 

 long; bractlets subulate; involucre green, the scales lance-oblong, acute, 

 subeqiial, loosely imbricated, 2.5 mm. long, scarcely half the length of 

 the flowers : corolla in dried specimen white, 8 mm. long, with a rela- 

 tively long throat narrowed into a shorter tube, glabrous, e(iualled l)y 

 the bristles of the pappus; these somewhat unequal, barbellate, white 



