460 



SYNGENESIA NECESSARIA. 



Nutt. 2. p-182. 



Tussilago Integrifolia^ Mich. 2- p. 121. Willd. Sp< pi. S. p. 1964- 



Perdicium Semiflosculare, Walt, p. 204. 



Root somewhat tuberose^ perennial. Leaves oblong, lanceolate, some- 

 times obovate, with fine retrorse denticulations, which, in the mature leaf 

 are nearly obsolete, green and glabrous on the upper surface, covered with 

 a white very dense cottony tonientum underneath. Scapes several from 

 each root, six to ten inches long, tomentose, one-flowered; the flowers at 

 first nodding, becoming erect as the seed matures. Calyx imbricate. Scales 

 linear-lanceolate, appressed, clothed with a ferruginous tomentum, except the 

 midrib which is glabrous. Exterior ^ore/5 of the ray l6 to 20, glabrous, 

 white on the interior surface, purple on the outer; just within these is a se- 

 cond series of female florets with long styles and only the rudiment of the 

 corolla. Florets of the disk sterile, bilabiate, one lip broad, reflexed, 

 slightly three-cleft, the other lip deeply two-cleft, with the segments revo- 

 lute. See^f of the fertile florets oblong, striate, glabrous. 



Grows in dg-mp pine barrens. ^' 



Flowers March — April. 



SILPHIUM. Gen. Pl. 1334. 



Involucrum foliace 



Involucrum 



iim, sqiiarrosum 



Se 



leafy, 



squarrose. Seeds com 



mtna compressa^ ob- pressed, obcordate, e- 

 cordata, emarginata^ marginate, two-tooth- 

 bideutata. Recepta- \ ed. Receptacle chaffy 

 culum paleaceum.* 



* GuMiMIFERUM. E. 



S. caule erecto, luspido, gummi- 

 feroj foliis sinuate pinnatifidis, sub- 

 tus subhispidis; floribus majusculis, 

 axillaribus subsessilibus; involucri 



hisnidis. 



vatis, acummatis 

 E, 



Stem erect, hispid, bearing gum; 



under- 



leaves 



sinuate, pinnatifid 



neath somewhat hispid; powers 



large, axillary, nearly sessile; s 



cales 



acummat 



hispid along the margin 



Root perennial? Stem two to three feet high, robust, very hispid and 

 rough, exuding whenever wounded a terebinthine gum, so abundant that it 

 sometimes I am told almost encrusts the plant. Leaves sinuate, pinnatifid, 

 hispid on the under surface, particularly along the veins, the segments very 

 acute, and generally more remote and incised than in the other pinnatiiiu 

 species. Flowers larger than those of any other species in this genus that I 

 have seen, axillarv, on short souarrose neduncles. Scales of the involucrum 



