COMPOSITE. 155 



calyx or pappus. Seed destitute of albumen. Herbs, rarely 

 shrubs. Leaves alternate or opposite, without stipules. Flowers 

 collected in dense heads upon a common receptacle, surrounded 

 by an involucre. 



SUBORDER I. TUBULIFLOR^. 



Corolla of the perfect flowers tubular, with 5, rarely 4, equal 

 teeth. 



I. VERNONIACE.E. Style of ihe perfect flowers cylindrical ; its 

 branches long and subulate, occasionally slwrt and blunt, always 

 covered over wiih bristles. 



1. VERNONIA. SfcArc*. Iron Weed. 

 (Tn honor of Mr. WiHiam Vernon, an English botanist,) 



Heads several or many-flowered ; the flowers all equal. 

 Involucre imbricate. Receptacle mostly naked. Corolla regu- 

 lar, 5 -cleft. Filaments smooth. Achenia with a cartilaginous 

 callus at the base. Pappus often double ; the inner row of 

 numerous bristles ; the outer one much shorter and often chaffy. 



V. Noveboracensis Wittd. : stem erect, smoothish ; leaves on short petioles, 

 elliptic-lanceolate, pubescent beneath ; heads numerous, 20 30-flowered ; 

 scales of the involucre ovate, appressed at base, the apex produced into a 

 spreading filiform seta : achenia smooth, shorter than the pappus. 



var. prfEalla Torr. fy Gr. : scales of the involucre acute or acuminate, 

 unarmed or only a part of them filiform at the top. V. prcealta Willd. 



Wet meadows. Can. to Flor. W. to Miss. Aug., Sept. 1}.. Stem stout, 

 3 6 feet high, striate, often purple, branching at the top. Flowers in a large 

 terminal corymb, purple. In some places it is an obnoxious weed. 



Common Iron-weed. 



2. ELEPHANTOPUS. Cass. Elephant' s-Foot. 



(From the Greek sXe^aj, an elephant, and TTOVJ, afoot ; in allusion to the form 

 and position of the leaves in one species.) 



Heads 3 5 -flowered, densely crowded into clusters. Invo- 

 lucre compressed, in two rows; the leafets dry, oblong, the 

 inner ones often 3 -nerved. Receptacle naked. Corolla pal- 

 mate ; segments acuminate, one sinus deeper than the rest. 

 Achenia somewhat compressed, many-ribbed, oblong, pilose. 

 Pappus in one or two rows of several chaffy bristles, dilated at 

 the base. 



E. Cardinianm Wittd. : stem branched, hairy ; leaves scabrous ; radical 

 ovate, or obovate-oblong, crenate-serrate, attenuate at the base ; cauline ob- 

 long, narrow at base ; floral ovate-oblong. 



