254 COMPOSITiE. Zinnia. 



Z. aC6r6sa, Gray. Cinereous-pubescent or glabrate : leaves acerose-filiform, very obscurely 

 oiie-nerved, half-iuch or more loug : ligules 3 to 6 Hues long : style-branches with subulate- 

 ovate tips. — PI. Wright. 1. c. Diplothrix acerosa, DC. Prodr. v. Gil. — Hills, S. W. Texas, 

 Wright. (Adj. Mex.) 



85. SANVITALIA, Lam. (Samntali, name of a noble Italian family.) 

 — Mostly low and branching herbs, of Mexico and its border ; with opposite and 

 more or less petioled leaves, almost always entire, and rather small heads termi- 

 nating the branches, ours and most of the species annuals. — Jour. Hist. Nat. 

 ii. (1792), 17G, t. 33 ; 111. t. 686; Cav. Ic. iv. 31, t. 351 ; DC. Prodr. v. 628. 

 Lorentea, Ort. Dec. iv. 42, t. 5. 



§ 1. Involucre of 2 or 3 series of bracts, their tips commonly herbaceous : 

 fructiferous receptacle from fiat to strongly conical ; its chaffy bracts soft or 

 shorter than the flowers : disk commonly dark purple or brownish : rays yellow 

 or turning whitish in age : ray-akenes mostly triangular ; the comparative smooth- 

 ness, granulation, or murication of disk-akenes inconstant. 



S. OCymoides, DC. A span or two high, diffusely spreading, hispidulous or hirsute: 

 leaves oval, obtuse, abruptly contracted into the petiole : ligules shorter than the akene and 

 shorter than the three slender-subulate diverging awns : disk-akenes all wingless, cjuadran- 

 gular-compressed, sometimes 1-2-^wned. — S. ocymoides & S. tragicefolia, DC'. 1. c. — South- 

 ernmost border of Texas on the Ilio Grande, Berlandier, Schott. (Adj. Mex.) 

 S. PROCUMnENS, Lam. 1. c. (S. villosa, Cav. Ic. 1. c), a Mexican species not uncommon in 

 cultivation, has conspicuous ligules much exceeding the awns at their base, and flattened disk- 

 akenes, some of them winged and 1-2-aristellate, some not ; and the receptacle, at first barely 

 convex, may become even acutely conical in age. S. acinijolia, DC. 1. c, appears to be only 

 a form of it. 



S. ANGUSTiFOLiA, Eugclm. iu Gray, PI. Wright, i. 112, of Northern Mexico, has similar 

 akenes and similar receptacle, but rays nearly as short as those of S. ocymoides ; the chaff of 

 the receptacle disposed to be rigid-tipped as in the following. 



§ 2. Involucre a single series of dry bracts : fructiferous receptacle strongly 

 and acutely conical ; its chaffy bracts conspicuous and with rigid cuspidate tips : 

 rays white : disk pale : leaves rarely denticulate. 



S. Aberti, Gray. Erect, at length a foot high, with ascending branches, minutely pubescent 

 or hispidulous, glabrate : leaves lanceolate or nearly linear, 3-nerved, narrowed into a mar- 

 gined petiole : rays 1 to 3 lines long : akenes all corky-thickened ; those of the ray almost 

 terete, narrowly 4-sulcate, bearing 3 very short and stout nearly conical awns or tubercles ; 

 of the disk compressed-quadrangular, wingless, awnless, or sometimes minutely uuiaristellate. 

 — PI. Feudk 87, & PI. Wright, i. 111. — S. W. Texas, New Mexico, and S. Arizona. 



86. HEL1I6PSIS, Pers. ("HAtos, the sun, oi//t?, likeness, from resemblance 

 to the Sunflower.) — American perennials (or a Mexican and South American 

 species annual) ; with loosely branching stems, ovate or oblong and veiny mostly 

 serrate 3-ribbed or triple-ribbed leaves, on naked petioles, and pedunculate showy 

 heads ; the rather numerous rays yellow, and the disk yellowish. Fl. summer 

 and autumn. — Syn. ii. 473; Torr. & Gray, Fl. ii. 302; Benth. & Hook. Gen. 

 ii. 358. 



H. lee vis, Pers. Smooth and glabrous or nearly so throughout, 3 or 4 feet high : leaves 

 bright green, thinnish, oblong-ovate or ovate-lanceolate from a truncate or slightly cuneate- 

 decurrent base, acuminate, coarsely and sharply serrate with numerous teeth (3 to 5 inches 

 long) : heads somewhat corymbose : rays broadly linear, an inch long, at length marcescent 

 and decaying away : akenes wholly glabrous and smooth, the summit wholly truncate or ob- 

 scurely 2-4-toothed. — Pursh, Fl. li. 563 ; Dunal, Mem. Mas. v. 55 ; Hook. Bot. Mag. t. 3372 ; 



