OF ARTS AND SCIENCES. 109 



above, paler and subglabrous below, 1^-2 inches long; the cauline 

 usually a single pair, reduced to short linear bracts : heads including 

 rays 1 \ inclies broad : outer bracts of the involucre ovate, commonly 

 purplish, obtusish, 4 lines in length, the inner somewliat longer, nar- 

 rower and ciliolate: rays purplisli white, oblong, conspicuously 3-toothed, 

 exceeding half an inch in length, abruptly contracted below into a very 

 slender tube : receptacle elongated : chaff filiform : achenes black, 

 glabrous. — In pine forests, Nevado de Toluca, 12,000 ft., September, 

 1892 (n. 4226). 



Vekbesina oncophora. Shrub : younger parts gray-tomentu- 

 lose : leaves lance-elliptic, acuminate in each direction, thickish, 3-7 

 inches long, finely and rather regularly serrate, scabrous above, tomen- 

 tose and pulverulent beneath with yellowish white hairs ; petioles ^-^ 

 inch long ; a small fleshy folded finally deciduous appendage occurring 

 on each side of the base : corymbs compound, many headed : heads 

 4 lines in diameter : scales of the involucre acute, not at all foliaceous : 

 rays yellow, about 8, exserted 2-3 lines : disk flowers pubescent : 

 achenes rather narrowly winged, 1^ lines long, hispidulous upon the 

 faces. — Sierra de las Cruces, State of Mexico, October, 1892 (n. 4310) ; 

 Bourgeaus 967, Forest of San Nicolas, near Mexico, 1865-66. Near 

 V. persici/olia, DC, but diflTering in the greater pubescence and finer 

 serration of the leaves, the presence of the peculiar excrescences on 

 the stem at the base of the petioles, and in the pubescent corollas. 



Tridax Palmeri, Gray, var. indivisa. Rough pubescent, 

 almost hirsute : leaves ovate, rather irregularly dentate, scabrous, 

 undivided. — Caiion ledges, mountains near Lake Chapala, Jalisco, 

 November, 1892 (n. 4332). This plant corresponds except in its 

 pubescence to Parry & Palmer's 489. But both of these specimens 

 differ so conspicuously from the form of the species with divided leaves, 

 represented by Parry & Palmer's 482^ and 490, and Schaffner's 236, 

 that it seems best to characterize them as a variety. Parry & Palmer's 

 489 corresponds rather closely with this variety in its foliage, but is 

 much less pubescent, and in this regard furnishes a transition to the 

 smoother forms with undivided leaves, represented by the other type . 

 specimens (Parry & Palmer's 482-^ and 496) and by Schaffner's 236. 



SCHKUHRiA GLOMERATA. Roots fibrous : Stem simple, erect, 

 striate, glandular-hirsute, Ih feet high: the lower leaves opposite, 

 petiolate, minutely resinous-dotted, palmately 3-parted to the base ; 

 segments linear or linear-oblong, the middle one sometimes toothed, 

 the lateral ones very deeply bifid : the upper leaves alternate, sessile, 

 simplified : heads aggregated at the ends of the branches : i:)edicels 



