218 COMPOSITE. (COMPOSITE FAMILY.) 



cled, 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 wcdgc-obovate, 

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

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

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

 North Carolina. November. Shrub G- 12 high. 



3. B. angustifolia, 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 bicaudate. 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. (Conyza bifrons, Ell.) Margins of 

 pine-barren ponds, Florida to North Carolina. September. Stem 1 - 2 high. 

 Flowers pale purple or white. 



2. P. fcetida, DC. Minutely pubescent and glandular ; leaves large, 

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

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

 cels ; involucre smoothish, often purplish. (Conyza Marylandica, Ell.?) 

 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-lanceolate 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' - 3' 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. 



