170 COMPOSITE. 



homogamou!^ ; when the marginal ones are pistillate or neuter and the 

 others are perfect or staniinate, the head is termed hderoyainous. The 

 flowers with a strap-shajied (liyulalc) corolla are termed rays, or ray-Jlow- 

 ers ; and when these are present the head is termed radiate. A head 

 composed entirely of tubular Uowers is termed discoid, and tubular 

 flowers occupying the centre of a radiate flower make what is called the 

 disk. In some case:: the staniinate and T)istillato flowers fire ujion difl'erent 

 individuals — then the plant is diuxuuus. Tlie receptacle is ^w/mceows or 

 chq//'y when covered with membranaceous scales, and naked when destitute 

 of them. 



To indicate, even in the most general way, the medicinal character of 

 such an immense orderof plants is well-nigh impossible. It will sutKce to 

 say that very many of tlunu possess tonic properties, few are aromatic, 

 most are disagreeable, and iioriO are poisonous. 



LIATRIS. — Button Snakeuoot. 



Character of the Genus. — Heads few- or many-flowered ; flowers all 

 tubular, perfect. Scales of the involucre few or many, imbricate, ap- 

 pressed. Ksceptacle naked. Corolla 5-lobed, the lobes usually elongated. 

 Branches of tlie style much exserted, roundish or sonaewhat flattened, ob- 

 tuse. Achenia round, slender, tapering to the base, 10-ribbed. Pappus 

 of 10 to 40 plumose or barbellate bristles. 



Perennial herbs, with simple stems and tuberous roots. Leaves alter- 

 nate, usually lanceolate or liueiu', entire, with a rigid margin, often resin- 

 ous-dottod. Heads in an elongated sjiikc or raceme, sonietimcs panicu- 

 late, rarely cymoso ; flowers showy, rose-jmrple, rarely pale or white. 



Liatris spicata Wiiklenow. — Button Snakeroot, DeciVs Bit, Colic Root. 



Description. — Heads 8- to 12-flowered, one-fourth to one-half inch long, 

 sessile, in an elongated spike ; involucre cylindrical-campaiuilate, obtuse 

 at the base, the numerous scales appressed, obtuse, punctate, and with 

 narrow, scarious, purplish margins, the inner ones oblong, the outer ovate 

 or oval. Pappus densely barbellate ; achenia hairy. 



biem erect, 3 to 5 feet high, smooth, leafy, proceeding from a roundish 

 corm or tuber. Leaves very numerous, hairy on the veins beneatli. punc- 

 tate, those of the stem linear, diminisliing in length from below upward, 

 the radical ones also linear, but very long. 



Hibilal. — In moist ground from Southern New York to Wisconsin and 

 southward. . 



Liatris odoratissima "Willdenow. — Vanilla Plant, Deer's Tongue. 



JJescriplion. — Heads small, 4- to 10-flowered, in a panicle or corymb ;' 

 scales of tlu; involucre f(!W, slightly imbricated, spatulatc-obhrng. Corolla- 

 lobes short, ovate. Pappus minutely barbellate, not plumose. 



Stem simple or branched above, 2 to 4 feet higli, fi*om a short rhizome, 

 not tuberous. Leaves thic'v, somewhat glaucous, the radical ones obovate- 



