376 ORDER LXVIII.— COMPOSITE. 



florets perfect. Scales of the involucre lanceolate, subulate, im- 

 bricate, appressed. Achenia villous, terete, linear. Hirsute 

 herbs. Leaves alternate, crowded, sessile. 



1. I. divarica'tus. Stem erect, slender, hispid, scabrous, branching 

 toward the summit. Leaves linear-lanceolate, acute, ciliate, serrate, 

 hispid, the lower ones attenuate at the base. Flowers in long divaricate 



f)anicles ; involucre many-leaved, scales pubescent on the back, linear- 

 anceolate. Seed hispid ; pappus reddish-brown, the exterior wanting. 

 — Yellow. 2f. Aug. — Oct. Southern Georgia. 1 — 2 feet. 



Genus XXIV.— PRIONOP'SIS. Nutt. 

 (From prion, a saw, and opsis, resemblance, in allusion to the teeth of the leaf.) 



Heads many-flowered, hemispherical, ray florets in a single 

 series, numerous, pistillate, disk perfect. Scales of the invo- 

 lucre numerous, imbricate, squarrose, with the exterior ones 

 squarrose. Receptacle alveolate, flat. Achenia short, glabrous, 

 striate. Pappus deciduous, consisting of unequal, scabrous bris- 

 tles, some longer than the corolla of the disk. Herbaceous 

 plants, with alternate, serrate leaves. Flowers yellow. 



1. P. Ciiapman'ii, (T. & G.) Stem simple, virgate, hirsute-pubescent. 

 Leaven numerous, lanceolate or linear, glabrous, setaceously serrate. — 

 Yellow. U- Middle Florida. 1—2 feet. 



Genus XXV.— HETEROTH'ECA. Cass. 

 (From hetero, different, and theka, envelope.) 



.Heads many-flowered, those of the ray pistillate in one series, 

 those of the disk perfect. Scales of the involucre in a few se- 

 ries, linear, appressed, with spreading points. Receptacle plain, 

 alveolate. Achenia of the ray oblong, smooth, without pappus, 

 those of the disk cuneate, villous. Pappus of the disk double, 

 the exterior of short chafTy bristles, the interior of capillary 

 bristles. Herbaceous plants, hirsute or strigose, paniculately 

 branched. Flowers yellow, pappus colored. 



1. H. sca'bra, (D. C.) Stem branching from the base, scabrous, divar- 

 icate, glandular, hairy. Radical leaves oval, on petioles, dilated at the 

 base, coarsely toothed, cauline ones cordate-ovate, acute, amplexicaul, 

 all scabrous. Flowers in compound terminal panicles; involucre cylin- 

 drical; leaflets numerous, acute, linear, viscid ; ray florets lanceolate, 

 nerved ; exterior pappus a marginal ring, the interior wanting. — Yellow. 

 If. October. On the seacoast. 2 — 3 feet. 



Genus XXVI— CHRYSOP'SIS. Nutt. 

 (From chrusos, gold, and opsis, like.) 



Involucre imbricate; ray florets pistillate, those of the disk 

 perfect. Anthers naked at the base ; pappus double, the outer 

 chaffy and minute, the inner pilose and scabrous, many-rayed. 

 Seeds obovate, villous. Receptacle naked. 



