OF ARTS AND SCIENCES. 891 



pappo e setis 20 longe plumosis corolla disci dimidio achenio pauUo 

 brevioribus. — Among rocks midway on the mountains above Bato- 

 pilas, Palmer, 285. 



Tridax bicolor, Gray, PI. Fendl. 104. Mountain-sides above 

 Batopilas, Palmer, 130. Rays bright white (disk yellow) : but speci- 

 mens of Pringle (638), from near the city of Chihuahua, have the rays 

 tinged with rose. Both are larger-leaved than the original specimen 

 of coll. "Wislizenus. 



Tridax leptophtlla. Parce hispidula ; caule (e radice annua ?) 

 erecto patenti-ramoso pedali ; ramis superne longe nudis moiiocephalis ; 

 foliis ternato- nunc biternato-partitis in segmenta angiisto-linearia elon- 

 gata integerrima, summis nunc integris fere filiformibus ; capitulis 

 multifloris ; disco fructifero fere conico (semipollicari) ; involucro lato- 

 campanulato, bracteis ovalibus vel orbiculatis membranaceis purpuras- 

 centibus glabris ; paleis receptaculi demum alte conici muticis ; ligulis 

 rotundato-quadratis tubo suo villoso subduplo longioribus discique 

 corollis aureis ; pappi setis rigidis breviter plumosis achenio turbinato 

 aequilongis. — Sandbars of the river near Batopilas, Palmer, 425. 



Perityle microcephala, Cinereo-puberula, e radice forte annua 

 ramosissima, diffusa, floribunda ; foliis omnibus oppositis deltoideis seu 

 dilatato-ovatis basi truncatis grosse paucidentatis repandisve (lin. 4-8 

 longis) ; capitulis subcyraosis (lin. 2 altis) ; involucri late campanulati 

 bracteis oblongis ; ligulis albis quadratis lineam longis ; corollis disci 

 brevibus ; styli fl. herm. ramis cono subulato terminatis ; acheniis 

 oblongis marginibus dense villosis ; pappo coroniformi sat conspicuo 

 ssepius cum aristellis 1-2 tenuibus nudis achenio circiter dimidio brevi- 

 oribus. — Rocky hills near the city of Chihuahua, Oct. 8, just coming 

 into blossom, Pringle, 571 (too scanty for distribution*), and mountains 

 above Batopilas late in October, with mature akenes. Palmer, 208. 

 The delicate awns of the pappus under the lens are either quite 

 smooth or occasionally with one or two denticulations. 



Baiiia Neo-Mexicana, Gray, Proc. Am. Acad. xix. 27, & Syn. 

 Fl. i." 333. North of Batopilas, Palmer, 399 ; also coll. by Pringle. 



ScHKUHRiA WisLizENi, Gray, PI. Fendl. 96. About 150 miles 

 north of Batopilas (therefore not far from where it was discovered by 

 Wislizenus), Palmer, 387. A larger and much-branched form. 



IIymenotiikix Palmeri. Ultrapedalis e radice forte annua, sub- 

 glabra ; foliis ternatipartitis et segmentis subpinnatipartitis in lobos 

 3-7 angusto-lineares integerrimos, summis parvulis trifidis ; inflores- 



* The rare Perityle Parri/i, Gray, is, however, in Pringle's distribution, 183. 



