396 ORDER LXVm. COMPOSITE. 



Genus LVI.— YERBESI'NA. L. 

 (Name altered from Yerbena.) 



Involucre many-leaved, in a double series ; ray florets pistil- 

 late, about 5 ; disk florets perfect. Receptacle cLaffy ; pappus 

 2-awned. 



1. V. Viegin'ica, (L.) Stem eroet, irregularly winged, pubescent, 

 slightly furrowed. Leaves alternate, broad-lanceolate, acute, attenuate 

 at the base, dentate, pubescent and scabrous on the upper surface, to- 

 mentose beneath. Flowers in terminal corymbs ; involucre imbricate, 

 pubescent, shorter than the disk ; ray florets about 3, of the disk about 

 15. Seed hairy, compressed ; chaff hairy, — White. 2^. Aug. — Sept. 

 Middle Car. and Geo. 3—6 feet, 



2. V. sinua'ta, (Ell.) Stem erect, pubescent, winged toward the base, 

 striate. Leaves alternate, sessile, spatulate, or ovate ; those on the 

 middle of the stem sinuate, with acute lobes, scabrous on the upper sur- 

 face, pubescent beneath ; involucre pubescent, shorter than the disk ; 

 ray florets 3 — 5. >See(/ winged, cuneate. — White. If. Oct. — ISov. On 

 the sea-coast. 4 — 6 feet. 



3. V, siegesbeck'ia, (Mich.) Stem erect, pubescent, 4 winged branch- 

 es, bracteate. Leaves opposite, ovate, acuminate, denticulate, pubes- 

 cent, alternate at the base. Flowers in fastigiate corymbs ; involucre 

 pubescent ; ray florets 1 — 3, 3-toothed. Seed hispid, obovate ; chaff 

 pubescent. — Yellow. If. June — Aug. Common. 4 — 6 feet. 



Genus LVIL— XIMENE'SIA. Cav. 

 (Dedicated to Ximenes.) 



Heads many-flowered ; ray florets in a single series, pistillate ; 

 disk florets perfect ; scales of the involucre in 2 series. Recepta- 

 cle flat, chaffy ; chaff embracing the achenia. Achenia flat, 2- 

 awned. 



1. X. encelioi'des, (Cav.) Stem erect, eanescent. Leaves opposite, 

 or sometimes alternate, cordate-ovate, serrate ; petiole dilated at the 

 base. — Yellow. Probably introduced. 



Sub-tribe III. 



Genus LVIIL— FLAVE'RIA, Juss. 

 (From flatus, yellow.) 



Heads few-flowered, in glomerate fascicles, discoid, or with 1 

 ray floret. Involucre oblong, with 3 — 4 scales, the outer ones 

 broadest. Receptacle naked. Achenia oblong, striate, glabrous. 



1. F. linea'ris, (Laga.) Stem glabrous or slightly pubescent, sufiFruc- 

 ticose. Leaves opposite, sessile, entire or toothed, linear, somewhat 

 fleshy. — Pale yellow. Coast of East Florida. 



