200 COMPOSITE. 



Wet shady woods. Arct. Amer. to Louis. W. to Oregon. June, July. *4. - 

 Stem 1 2 feet high, branched above, often woolly. Heads middle sized, nume- 

 rous, on long slender peduncles which are thickened near the involucre ; rays 

 812, and with the disk yellow. Golden Groundsel. Squaw-weed. 



3. S. Balsamitce Muhl. : stem erect, villous at base ; radical leaves ob- 

 long-lanceolate, dentate-serrate, on long petioles ; cauline lyrate-pinnatifid, 

 sessile, the segments toothed ; heads in a compound umbellate corymb. 



Moist grounds. Arct. Amer. to Louis. W. to Oregon. June, July. 1\.. 

 Stem 1 V feet high, densely woolly at the base. Heads rather small, yellow ; 

 rays 8 12, narrow ; disk flowers about 20. Balsamita-like Groundsel. 



4. S. obovatus Muhl. : stem erect, smoothish ; radical leaves varying from 

 roundish-obovate to oblong-spatulate, crenate-serrate, petiolate ; cauline 

 pinnatifid, toothed, sessile ; heads in a nearly simple somewhat umbelled 

 corymb, on long peduncles which are scarcely thickened at the summit. 



Rocky woods. Arct. Amer. to Louis. W. to Oregon. June, July. Ij.. Stem 

 a foot high, branched at the summit. Heads rather small, yellow ; rays about 

 10. Torrey & Gray consider this and the preceding species, as mere varieties 

 of S. aureus ; to which also they refer -S'. lanceolatus Oakes and S. gracilis 

 Pursh. Obovate- leaved Groundsel. 



5. S. tomentosus Mich.: white -tomentose and woolly; radical leaves 

 oval-oblong or oval-lanceolate, serrulate-crenate, toothed at base, on long 

 petioles ; cauline oblong, somewhat divided ; corymb small, somewhat um- 

 belled. (S. integrifolius Nutt. Cineraria integrifolia and heterophylla 

 Pursh. 



Dry rocks on the Blue Mountains, Penn. Pursh. S. to Flor. May, June. 

 %. Stem 1 2 feet high. Heads yellow, larger than in S. aureus ; rays 12 15, 

 elongated. Downy Groundsel. 



6. S. elongatus Pursh. : smooth ; radical leaves spatulate, serrate, atten- 

 uated into a petiole ; cauline pinnatifid, toothed, very remote ; heads on 

 elongated peduncles, arranged in a somewhat umbelled corymb. 



Rocks on banks of streams near Easton. Penn. July, Aug. 01. Resembles 

 S. BalsamitcE, but is destitute of ray flowers. Pursh. Elongated Groundsel. 



V. CYNARE.E. Style in the perfect flowers thickened near the sum- 

 mit, and often fringed at the tumor ; its branches distinct or united, 

 pubescent externally. 



53 ; CENTAUREA. Linn. Knap Weed. Blue Bottle. 



(From the Centaur Chiron, who is said by this plant to have cured himself of 

 a wound received from Hercules.) 



Heads many-flowered ; ray flowers mostly large and sterile, 

 funnel-form, sometimes wanting. Scales of the involucre imbri- 

 cate, various. Receptacle bristly-paleaceous. Achenia com- 

 pressed. Pappus mostly in many series, pilose, sometimes 

 wanting. 



1 . C. Jacea Linn. : stem erect, branched ; leaves linear-lanceolate ; 

 lower broader and toothed, petioled ; scales of the involucre scarious and 

 torn, the outer pinnatifid ; heads radiate ; pappus very short or r; -rie. 



