SYNGENESIA NECESSARIA. 



463 



rather obtusCj slightly fringed. Florets of the ray scarcely exceeding twelve, 

 nearly an inch long, 



I suspect that some genuine species among the sinuate-leaved Silphiums 

 are yet undefined. 



Grows in dry pine barrens. 

 Flowers May — August. 



/ 



4, Terbinthinaceum. 



5. caule laevi; foliis 

 radicalibus amplis, ro- 

 tundato vel reniformi- 

 cordatis, sublobatis, 

 dentatisque, caulinis al- 

 ternis, ovatis, serratis, 

 scabris; panicula com- 

 posita, multiflora. 



Lin. 



Stem smooth; leaves 

 of the root large round 

 or reniform, cordate. 



lobed 



and 



slightly 

 toothed, of the stem 

 alternate, ovate, ser- 

 rate, scabrous; panicle 



compound, many flow- 

 ered. 



IK 



Sp.pl. 3. p. 2331. 



182. , 



Mich. 2- p. 145. Pursh, 2- p. 577- Nutt. 2. p. 



Stem erectj four to five feet high, glabrous. Root leaves deeply cordate^ 

 oblong or round, toothed, when luxuriant slightly lobed along the raargin- 

 Flotcers more numerous than usual in this genus, in large scattered corym- 

 bose panicles. Scales of the involucrum nearly ovate, the exterior rather 

 acute, the interior generally obtuse. Florets of the ray ten to twelve, about 

 an inch long. 



This species appears subject to some variations. In specimens sent me 

 hy Dr. Schweinitz from Salem, North-Carolina, the root leaves were nearly 

 reniform, simply toothed and very scabrous underneath. In specimens col- 

 lected in the western districts of Georgia and Alabama, where it appears 

 to be more luxuriant, the leaves were lobed and angled, and nearly glabrous 

 underneath. In the flowers I can perceive no difference. 



Grows along the mountains. 



Flowers July—August. 



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