Oedee '70.— OOMPOSITJffi. 44 ^ 



leafy, the inner cliaffy ; receptacle flat, chaffy ; achenia of the ray ob- 

 compressed, obovate, each embraced by a chaff-scale ; achenia of the 

 disk abortive ; pappus a small, 2 to 3-toothed crown. — 21 A little pros- 

 trate herb, with opposite Ivs. and solitary, pedunculate, bright yellow 

 Vernal fls. , 



fc!. Virginiaaum L. — In rich shady soils, Md. to 111., common southward to the 

 Gulf. One of the earliest flowers of spring. Plant flat on the ground, hirsute, 

 at first acaulescent, at length caulescent and ascending. Lvs. ovate, tapering to 



. a petiole, crenate. Eays expanding 1 to 9". Feb. — May. 



'41. SIL'PHIUM, L. EosiN-wEBD. (The ancient name of some 

 resinous plant.') Heads many-flowered ; ray-flowers numerous, in 2 or 

 3 rows, fertile, outer row ligalate ; disk-flowers sterile ; involucre cam- 

 pahulate, scales in several series, leafy and spreading at summit ; recep- 

 tacle small-, flat, chaffy ; achenia broad, flat, obcompressed, crowned 

 with a 2-toothed pappus. — 2J! Stout, coarse, resinous herbs.- Hds. large. 

 Fls. yellow. 



* stem nearly, leafless, scape-llfco. Lv3. very large, alternate, mostly radical Nos. 1 — 8 



* Stem le.afy. — LeaVes vei-ticillate in whoi'ls of Ss, rarely 4s Nos. 4, 5 ^ 



— Leaves opposite, rarely the highest scattered Nos. 5—7 



—Leaves alternate (the lowest opposite or veiticillate oi- alternate) No. S 



—Leaves connate-perfoliato No. 9 



X S. lacini^tum L. Polar Plant. Very rough, with white, hispid hairs; Its. 

 alternate, pinnatsly parted, lower petiolate, segments sinuate-lobed or entire ; 

 hds. spioate, distant; scales ovate, appendaged and squa/rrous at apex. — Western 

 States to Tex., producing columns of smoke in the burning prairies by its co- 

 pious resin. Stem 3 — lOf high. Lower lvs. 1 — 2f long, much divided, resem- 

 bling those of some thistles. Heads 4 — 8, very large, with large, yellow rays. 

 Jl.— Sept. 



2 S. terebinthinaoeum L. Prairie Buhdook. St. and ped. glabrous ; hs- 

 mostly radical, ovate and ovate-oblong, cordate, dentate-serrate, obtuse, scabrous, on 

 long petioles ; hds. few^, paniculate ; scales roundish and oval, glabrous, rays about 

 20. — Prairies, Western and Southern States. Plant exuding resin. Stem i — 8f 

 high, nearly naked and simple. Leaves 1 — 2f long, 1 — 16' wide. Involucre 

 globous. Hds, 1' diam., rays 1' long. Achenia narrowly 2-winged. Jl. — Sept. 



/3. PINNATIPIDUM. Lvs. more or less deeply lobed orpinnatifid. — Prairies, etc., 

 with the other form. (S. pinnatifidum Ell.) 



3 S. comp6situni Mx. Glabrous throughout; st. slender, almost naked, glau- 

 cous ; lvs. radical, on long petioles, deg)iy sinuate-pinnatifid, the segments sinuate- 

 globed or toothed ; hds. oorymbed, on long peduncles ; scales oval, obtuse ; ach. 

 rouudish-obovate ; rays about 10. — Barrens, N. Car. to Fla. (Peay). St. 3 to Of 

 high. Hds. T" diam., about 10-rayed, rays about as long (4'') as the involucre. 

 Jan. — Aug. 



/3. EENIFOBME. Lvs. roundish or reniform, cordate, slightly sinuate-lobed or 

 toothed. — Upper districts of Ga. and Car. 



4 S. trifoli^tum L. St. glabrous and often glaucous, terete or 6-sided; caaline 

 lvs. lanceolate, acute, scabrous above, smooth below, remotely dentate, on very 

 short petioles, verticillate m 3s or 4s ; upper ones opposite; hds. loosely oymose, 

 on rather long peduncles'; scales broadly ovate, rather obtuse, smooth ; ach. oval, 

 with 2 short teeth. — Dry woods and prairies, Ohio and Southern States. Stem 

 4 — 6f high.— Leaves 4^^6' by 1 — 2". Rays 12 — 16, expanding about 2^'. Ach. 

 3 to 4" long, 2 to 3" wide. Aug., Sept. 



5 S. integrifolium Mx. Scabrous ; st. quadrangular, striate, simple ; lvs. oppo- 

 site, sessile, ovate-lanceolate, entire or slightly dentate ; hds. in a close corymb ; 

 scales squarrous ; ach. roundish, broadly winged, with 2 Ixmg. feeiA.-— Western States 

 S. to Ga. Stem very rigid, 3 — 7 f high. Leaves rigid, lifoad and clasping at 

 base. Heads middle-size. Eays 12^^20. 1' in length. Ach. 4 to 5" long, 4" 

 'wide. Jl., Aug. 



