COMPOSITE. 171 



8. SONCHUS. Linn. Don. 



Involucre many-leaved, closely imbricate, dilated at base, 

 connivent at the summit. Receptacle pitted, scabrous, with 

 the elevated and torn margins of the pits slightly dotted. Flo- 

 rets indefinite, the mouth very villous without. Anthers acute- 

 ly bidentate at base. Stigjna hispid. Acines ancipital-com- 

 pressed, sulcate, transversely rugose, simple at the summit, 

 very soft, capillary, fugaceous ; rays very copious, unequal, 

 fasciculately connate at base Flowers yellow, corymbose, 

 rarely solitary. Syngenesia. JEqualis. 



1. S. oleraceus Linn. : leaves oblong-lanceolate, clasping, slightly 

 toothed and sinuate ; involucre smooth ; peduncles somewhat tomen- 

 tose. 



HAB. Waste grounds. Can. to Car. July Sept. 0. Stem 

 24 feet high, hollow and succulent. Peduncles axillary and 

 terminal, covered with a cotton-like down. Flowers yellow. 

 It differs from the generic character in its smooth receptacle. 

 Introduced. Soio Thistle. 



2. S. arvensis Linn. : root creeping ; leaves runcinate, denticulate, 

 cordate at base ; involucre hispid ; peduncles hispid, somewhat umbel- 

 led. 



HAB. Near cultivated grounds. N. S. If. Stem 2 feet high. 

 Floicers large, deep yellow. Introduced. 



3. S. spinidosus Biff. : leaves clasping, oblong, waved, prickly ; 

 flowers somewhat umbelled. 



HAB. Salt marshes. Mass. Aug. . Stem 2 feet high, smooth 

 or slightly hairy. Leqfets smooth, with teeth ending in short 

 spines. Flowers somewhat umbelled, small, yellow. 



9. CICHORIUM. Linn. 



Involucre surrounded with leafy scales. Receptacle some- 

 what chaffy. Pappis plumose, sessile, unequal, shorter than 

 than the acines. Syngenesia. JEqualis. 



C. intybus Linn. : leaves runcinate ; flowers axillary, sessile, in 

 pairs. 



HAB. Fields. N. S. July Sept. If. Stem 23 feet high, 

 with rough branches. Flowers large, blue. Introduced. 



Svccory. 



SUBORDER II. CARDUACEjE. 



10. ARCTIUM. Linn. 



Involucre globose, each of its scales with an incurved hook 

 at the extremity. Receptacle chaffy. Pappus simple, the 

 rays short. Syngenesia. Mqualis. 



A. lappa Linn. : leaves cordate, petiolate^unarmed. 



