238 COMPOSIT.E. (cOMroSITK KAMILV.) 



larj^o, soiiu'wliiit c-orymbose ; outer scales of tlie involiuTe lirou'lly ovate, leafy ; 

 rays iiumcruiis, narrow ; aclieuia 4 si<leil, siimolli. — Mountains of Morth (.'uro- 

 lina. liilriHliK-L'd. 



29. PLUCHEA, (ass. 



lluads inany-liowtTed, diseoid ; tliu ciiitral tlowers mostly perfect, imt ster- 

 ile, with the corolla dilated and fi-ckd't ; the otlicrs pistillate, slender, slightly 

 toothed. Anthers bicaudate. Scales of tlie involucre imbricated. Jieceptai;le 

 flat, mostly naked. Acheuia grooved or angled. J'appus a single row of 

 capillary slightly scabrous bristles. — Odorous mostly puiiescent and glandu- 

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

 flowers corymbose. 



1. P. bifrODS, DC. Stem .'^imjile, or s])aringly brancheil ; leaves oblong, 



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



heads clustered; involucre jnibe.scent and viscid. — Margins of pine barren 



ponds, Florida to North Carolina. Sept. — Stem l°-2° high. Flowers pale 



purple or white. 



i 



2. P. foetida, DC. Minutely ])ubescei)t and glandular; leaves large, 

 membranaceous, ovate-lanceolate, acuminate, serrate, tapering into a j)etiole; 

 corymlis axillary and terminal ; lieads rather small, numerous, on slender pedi- 

 cels ; involucre smoothish ; often purplish. — Damp soil, Florida, and north- 

 ward. Sept. — Stem 2°- 5° high. Leaves 5' - 8' long, resinous-dotted. Flow- 

 ers purple. 



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

 leaves ovate-lanceolate or oblong-ovate, acute, denticulate, nearly sessile; 

 heads rntlier large, in a dense corymb, on short and stout pedicels ; scales of 

 the involucre pubescent, the inner ones long-acuminate. — Salt marches, Flor- 

 ida to North Carolina. Sept. — 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, loosclv corvmbose; 

 scales of the involucre pubescent, the inner ones lanceolate, acute. — Swamps 

 and low ground, Florida. Sept. — Stem 1° - 2° high, with numerous spread- 

 ing branches. Leaves 2' -4' long. Flowers bluish jmrple. 



30. PTEROCAULON, Fll. 



Heads and flowers chiefly as in Pluchea. Scales of the involucre lanceolate, 

 imbricated iu several rows, caducous. Keceptacle minutely hairy. Acheuia 

 angled, pubescent. Pappus of numerous equal capillary Itristles. longer than 

 the involucre. — Perennial herbs. Leaves lanceolate, densely toniento.se and 

 hoary beneath, the margins broadly decurrent on the stem. Heads compactly 

 spiked. 



1. P. pycnostachyum, Fll. Stem rarely l)ranched, l°-2° high; 

 leaves wavy, smooth above; spike thick, woolly; flowers white. — Damp pine 

 barrens, Florida to North Carolina. June -July. 



