Trixis. COMPOSITE. 409 



4 to 8 inches long, thin-papyraceous ; lobes rounded, copiously fringed with spinulose teeth, 

 margined-petioled : scapes naked, equalling the leaves, bearing solitary or a few pedunculate 

 heads : bracts of the involucre rather few in three series, lanceolate, setaceous-acuminate : 

 pappus rather sordid. — Lag. in herb, ex Don; Gray, PI. Fendl. 110, PI. Wright. 1. c. Cla- 

 rionea runcinata, Don in Trans. Linn. Soc. xvi. 207 ; DC. 1. c. — Dry ground, E. & S. Texas, 

 Wright, Ball, &c. (Adj. Mex.) 

 P. nana, Gray. Leafy-stemmed, glabrous : rootstocks slender, creeping : first leaves small 

 and scale-like ; principal cauline leaves firm-chartaceous, orbiculate, dilated-obovate, or 

 ovate (inch or two long), coarsely spinulose-dentate, sessile or partly clasping the slender 

 stem : heads mostly sessile, solitary and terminal : bracts of involucre 3 or 4 series, thinnish, 

 acutish; the short outer ones ovate, innermost lanceolate, mucronulate: pappus white. — 

 PI. Fendl. 111. — Dry plains and rocky bluffs, S. W. Texas to Arizona, Wright, Palmer, &c. 

 (Mex., first coll. by Gregg.) 



# # Taller, 1 to 3 feet high, branching, especially above, leafy up to the corymbiform polycepha- 

 lous inflorescence : leaves closely sessile by sagittate-cordate or sometimes truncate base, densely 

 and spinulosely denticulate : heads 5-15-flowered, narrow, half-inch or less long, subsessile and 

 fasciculate-crowded or short-pedicelled, quite naked at base: involucral bracts thinnish, not 

 very many, in only three series : flowers rose-purple and sometimes white in the same species : 

 pappus white, soft. 



-(— Involucre 8-15-flowered ; its bracts not attenuate-acuminate. 



P. "Wrightii, Gkay. Glabrous throughout, or obscurely puberulent, but smooth : leaves 

 thin, oblong to nearly ovate (larger 4, smaller 1 or 2 inches long), often unequally or doubly 

 dentate: heads 8-12-flowered : involucral bracts all pointless and obtuse, or the narrow 

 innermost barely acutish: corollas pale rose to whitish. — PI. "Wright, i. 127, ii. 102; & 

 Proc. Am. Acad. xix. 60. P. Arizonica, Gray, Bot. Calif, i. 422, a form of drier districts, 

 rather more rigid, the involucral bracts all rounded-obtuse. P. Coulteri, Gray, Proc. Am. 

 Acad. xv. 40, as to pi. Parry & Palmer, no. 234. — Rocky hills and ravines, S. W. Texas to 

 S. Arizona; first coll. by Coulter, then by Wright. (Mex., Schaffner, Parry &, Palmer.) 



P. micro cephala, Gray. Scabro-puberulent and minutely resinous-glandular: leaves 

 more chartaceous, oblong, commonly obtuse, finely and closely denticulate- heads 10-15- 

 flowered, larger than in preceding (over half-inch long when well developed) : involucral 

 bracts scaberulous on the back, abruptly acute or mueronate-acuminate : corollas rose-color. 

 — PI. Wright, i. 127, & Bot. Calif, i. 422. Acourtia microcephala, DC. Prodr. vii. 66. — Cali- 

 fornia, on hills hack of Monterey? (Douglas), Santa Barbara, and San Diego. 

 +- -t- Involucre 5-6 flowered; bracts attenuate-acuminate : fully developed heads half-inch long. 



P. Thlirberi, Gray. Scabro-puberulent, viscidulous-glandular : leaves firm-chartaceous, 

 oblong-ovate,'denticulate and partly doubly dentate (larger 5 to 8 inches long) : involucral 

 bracts lanceolate, gradually tapering to a very acute point, scaberulous externally : corollas 

 sometimes deep rose-color, sometimes white.— PI. Thurb. in Mem. Am. Acad. v. 324, & 

 Proc. Am. Acad. xix. 59. — S. Arizona, on rocky hills, Thurber, Lemmon. 



206. TRlXIS, P. Browne. (Tpifr's, threefold, the corolla being trifid.) — 

 American, chiefly subtropical, fruticose or perennial herbaceous plants ; with en- 

 tire or merely denticulate leaves, and paniculately or corymbosely cymose heads, 

 of moderate size; the corollas yellow or sometimes whitish. — Hist. Jam. 312; 

 Lag. Amoen. Nat. i. 35. Perdicium, L., in part. 



T. angustifolia, DC. Suffruticose, fastigiately or corymbosely much branched, a foot or 

 two high, sericeous-puberulent, from subcanescent to glabrate, somewhat resinous-atomifer- 

 ous, leafy up to the heads : leaves sessile, rather rigid, from broadly to very narrowly lan- 

 ceolate, entire or denticulate with sparse mucroniform teeth (2 or 3 inches long) : heads 

 simply fascicled or singly terminating leafy branchlets, half -inch and more long, 9-12-flow- 

 ered, subtended by a few" lanceolate or linear bracteiform leaves which do not exceed the 8 

 or 10 linear-lanceolate and equal proper bracts of the involucre ; these in age gibbous and 

 indurated at base : receptacle copiously villous : corollas golden yellow ; outer lip of the 

 marginal ones quarter-inch long : pappus barely fulvous. — Prodr. vii. 69 ; Gray, PI. Wright. 

 i. 128, ii. 102. T. frutescens, Gray, Bot. Mex. Bound. 103, vars. T. Calif ornica, Kellogg 



