OliDEK i.X VIII.— COM PuSIT^. 381 



Genus XXXV.— SILPII'IUM. L. 

 (From silpfnon, a name of an ancient plant, transferred to this genus.) 



Involucre leafy, sqiiarrose. Ray florets pistillate, those of 

 the disk staminate. Seed compressed, obcordate, einarginate, 

 2-toothed. Iiece27tacle chaffy. 



1. S. lacinia'tum, (L.) Stem hispid, simple, nearly glabrous toward 

 the base. Leaves alternate, about 2 feet long and 1 wide, pinnatifid, 

 the segments toothed and sinuate, scabrous. Involucre consisting of 10 

 leaves, subulate, Ray JloretKnxxmQvoMS, about as long as the involucre. 

 Pappus 2 small awns. — Yellow. If. Aug. — Sept. Western Georgia 

 and Alabama. 8 — 12 feet. 



2. S. pinnatifi'dum, (Ell.) Stem glabrous. Leaves large, pinnatifid, 

 sinuate ; segments usually acute, upper surface glabrous, the under 

 slightly scabrous. Flowers in panicles, large ; involucre glabrous, with 

 the exterior leaves orbicular, the interior oval. — Yellow. If. July. 

 Western Geo. and Ala, 4 — 6 feet. 



3. S. coMPOs'iTUM, (Mich.) Stem glabrous. Leaves irregularly lobed, 

 siimate, sometimes pinnatifid, glabrous above, somewhat hairy beneath. 

 Flowers in terminal panicles; involucre with the leaves slightly ciliate. 

 — Yellow. If. May — Aug. Pine -barrens. 2 — 3 ftet. 



4. S. terebintuina'ceum, (L.) Stem erect, glabrous. Radical leaves 

 cordate or nearly orbicular, or reniform, sometimes lobed and dentate ; 

 cauline ones alternate, serrate, scabrous, ovate. Flowers numerous, in 

 corymbose panicles; exterior leaves of the involucre ovate, acute, the 

 interior obtuse ; ray florets 10 — 12. — Y^ellow. If. July — Aug. Moun- 

 tains. 4 — 5 feet. 



5. S. trifolia'tum, (L.) Stem glabrous, somewhat hexagonal, u^u illy 

 purple. Leaves ovate-lanceolate, serrulate, slightly scabrous on tlie 

 upper surface, glabrous beneath, the upper ones nearly sessile, the 

 lower ternate. Floivers in terminal corymbs ; involucre with ovatf, 

 ciliate, loosely appressed leaves; ray florets about 14. — YeUow. If. 

 Aug. — Oct. Mountains. 4 — 5 feet. 



6. S. terxa'tum. Stem terete, or slightly angled, glabrou-. Leaven 

 verticillate, by threes, lanceolate, acute, denticulate or serrate, slightly 

 scabrous on the U|>per surface, pubesci-nt along the veins beneath. 

 Flowers in terminal corymbs; involucre ciliate, with ovate, loosily ap- 

 pressed leaves; ray florets 12 — 11, long. — Yellow. If. Aug. — Oct. 

 Mountains. 4 — 6 feet. 



7. S. atropurpu'reum. Stem erect, terete, purple, glabrous. Leaves 

 mostly verticillate, by fours, numerous, the lower ones alternate, and 

 the uppermost scattered, the intermediate ones sometimes by threes ; 

 all lanceolate, scabrous, dentate, on ciliate petioles; midrib purple. 

 i^/o^<;(^rs in dichotoinous panicles; involucre ciliate, with ovate scales; 

 ray fioiei-s long, narrow. — Y'ellow. If. Aug. — Sept. Upper districts. 

 4—5 feet. 



S. S. denta'tum, (Ell.) Stem erect, purple, glabrous, L^eaves broad- 

 lanceolate, sinuate, toothed, hairy, scabrous, the lower ones opjjosite, 

 upper ones alternate, ses.-:ile. Flowers in terminal corymbs ; invuUicre 

 ciliate, with broad-ovate leaves; ray florets about 10. ov.tI. — Yt'Uow. 

 If. Aug. — Sept. Common, near Cnlloden. 2 — '■■• U. 



