Ageratum. composite. 65 



ally almost glabrous. In this country it has only been detected by Mr. Cur- 

 tis, wliose specimens seem to accord with the variety Mexicanum (A. Mexi- 

 canum, Bot. mag. t. 2524), except that the flowers are -white. 



9. SCLEROLEPIS. Cass. did. 25. p. 365, ^r. ; Less. syn. p. 136. 



Head many-flowered. Scales of the involucre linear, equal, in a double 

 series. Receptacle naked. Corolla tubular-infundibuUform, 5-toothed, gla- 

 brous. Branches of the style much exserted, somewhat clavate. Achenia 

 5-angular. Pappus of 5 almost horny short oval and obtuse scales, in a 

 single series. — A glabrous perennial (aquatic) herb ; with simple stems, pro- 

 cumbent at the base, terminated usually by a single head. Leaves verti- 

 cillate (5-6 in a whorl), linear, entire, 1-nerved (resembling those of Hip- 

 puris). Flowers pale purple. 



S. verticillata (Cass. 1. c..)—DC. ! prodr. 5. p. 114. Sparganophorua 

 verticillatus, Michx.! Ji. 2. p. 95, t. 42 ; Nutt.! gen. 2. p. 139 ; Ell. sk. 2. 

 p. 312. iEthuha uniflora, Walt. Car. p. 195. 



Shallow water in pine barrens. New Jersey (at Quaker Bridge !) to Flori- 

 da ! July-Sepl.— Stem 1-2 feet high, very leafy, a little pubesceiit at the 

 summit, as also the involucre. — We have a form from Florida, wuh very 

 slender stems, only about 6 inches high, and the involucre nearly glabrous. 



Div. 2. Adenosttlk^, DC. — Pappus composed of slender hair-like 

 bristles, either scabrous or plumose, in one or more series. 



10. CARPHEPHORUS. Cass, in bull, philom. 1816, Sf did. sci.nat. 7. 

 p. 149 ; DC. prodr. 5. p. 132. (excl. spec. no. 2?) 



Species of Liatris, Michx., Nult., DC. 



Heads many- (about 20-) flowered. Scales of the involuce imbricated in 

 3-5 series, ovate or lanceolate, appressed. Receptacle chaflTy ; the scales 

 (subtending the flowers) lanceolate or linear, rigid, 3-nerved, mostly shorter 

 than the flowers, deciduous with the fruit. Corolla more or less dilated 

 above ; the lobes ovate or lanceolate, mostly short. Anthers usually in- 

 cluded. Branches of the style exserted, cylindraceous, obtuse. Achenia 

 terete or somewhat angled, narrowed towards the base, 10-ribbed. Pappus 

 of numerous (30-40) barbellate (rarely minutely plumose) unequal bristles, 

 somewhat in a double or triple series. — Perennial herbs (mostly North Ameri- 

 can), with the habit of Liatris, from which the chaffy receptacle chiefly dis- 

 tinguishes it. Root, or caudex, thickened, but not tuberous. Stem simple, 

 or corymbose at the summit, leafy. Leaves impressed-punctate, rigid, en- 

 tire (or toothed ?) ; the cauline ones commonly appressed. Heads corym- 

 bose-cymose, rarely racemose. Flowers purple. 



This genus was established by Cassini on a specimen preserved in the lierbarium 

 of Jussieu, with no label or any inlication of its native country, wiience U has not 

 subsequently been recognized. De CandoUe having added a second species, founded 



VOL. II.-9 



