218 COMPOSITE. (composite family.) 



clcd, the terminal ones clustered; pappus of the fertile flowers 3-4 times as 

 long as the involucre. — Low ground, near the coast, Florida and northward. 

 Sept and Oct — Shrub 2° - 12° high. 



2. B. glomeruliflora, Pers. Branches angled ; leaves wedge-ohovate, 

 coarsely toothed, rigid ; the uppermost ohovate, entire ; heads very numerous, 

 in dense sessile axillary clusters ; pappus of the fertile flowers twice as long as 

 the involucre. (B. sessiliflora, Miclix.) — Swamps along the coast, Florida to 

 North Carolina. November. — Shrub 6°- 12° high. 



3. £. ailgUStifolia, Michx. Branches numerous, angled ; leaves linear, 

 entire; heads single, or 2-4 in a terminal cluster; achenia smooth. — Saline 

 marshes, Florida to North Carolina. Oct. — Shrub 4°- 8° high. Heads small. 



28. PLUCHEA, Cass. 



Heads many-flowered ; the central flowers mostly perfect, but sterile, with 

 the corolla dilated and 5-cleft; the others pistillate, slender, slightly toothed. 

 Anthers bicaudatc. Scales of the involucre imbricated. Receptacle flat, 

 mostly naked. Achenia grooved or angled. Pappus a single row of capil- 

 lary slightly scabrous bristles. — Odorous mostly pubescent and glandular 

 herbs, with alternate ovate or oblong serrate leaves. Heads of purplish flowers 

 corymbose. 



1. P. bifrons, DC. Stem simple, or sparingly branched ; leaves oblong, 

 acute, denticulate, strongly reticulated and rugose, cordate and clasping ; heads 

 clustered : involucre pubescent and viscid. (Convza bifrons, Ell.) — Margins of 

 pine-barren ponds, Florida to North Carolina. September. — Stem l°-2° high. 

 Flowers pale purple or white. 



2. P. fOBtida, DC. Minutely pubescent and glandular ; leaves lanre, 

 membranaceous, ovate-lanceolate, acuminate, serrate, tapering into a petiole ; 

 corymbs axillary and terminal ; heads rather small, numerous, on slender pedi- 

 cels ; involucre smpothish, often purplish. (Convza Marylandica, Eli?) — 

 Damp soil, Florida, and northward. September. — Stem 2°-5° high. Leaves 

 5'-8' long, resinous-dotted. Flowers purple. 



3. P. camphorata, DC. Minutely pubescent and glandular-viscid ; 

 leaves ovate-lancpolate or oblong-ovate, acute, denticulate, nearly sessile ; heads 

 rather large, in a dense corymb, on short and stout pedicels ; scales of the invo- 

 lucre pubescent, the inner ones long-acuminate. — Salt marshes, Florida to 

 North Carolina. September. — Stem l°-2° high ; the branches few and erect. 

 Leaves 2' - •".' long. Flowers light purple. 



4. P. purpurascens, DC. Tomentose and glandular ; leaves ovate- 

 lanceolate, acute or acuminate, sharply and somewhat erosely serrate, on slender 

 petioles; heads rather small, on slender pedicels, loosely corymbose ; scales of 

 the involucre pubescent, the inner ones lanceolate, acute. — Swamps and low 

 ground, Florida. September. — Stem l°-2° high, with numerous spreading 

 branches. Leaves 2' -4' long. Flowers bluish-purple. 





