404 COMPOSITE. CENTAuaEA. 



Subtribe I. CentauriEtE, DC. Heads discoid, many -flow er ed ; the marginal flowers usually 



neutral, with the corolla irregularly 5-cleft, and viuch larger than the disk-flowers. 

 Scales of the involucre imbricated, variously appendiculate. Pappus hairy, setose or 

 chafl'y, never plumose, sometimes wanting, 



42. CENTAUREA, Linn. ; Endl. gen. 2871. star-thistle. 



[ So named, because, with a plant of this genus, the Ccntmir Chiron is said to have cured himself of a wound received 



from Hercules.] 



Heads many-flowered ; the ray-flowers mostly large and sterile, sometimes wanting. Scales 



of the involucre imbricated, various. Receptacle setose. Achenia compressed. Pappus 



composed of rough bristles, sometimes nearly or quite wanting. — Herbs of varied aspect, 



with alternate leaves and solitary heads. 



1. Centaurea Cyanus, Linn. Bluebottle. French Pink 



Plant clothed with a loose cottony down ; stem erect, branching ; upper leaves linear, 

 entire , the lower ones toothed at the base ; scales of the roundish-ovoid involucre surrounded 

 with a scarious serrate margin. — Willd. sp. 3. p. 2291 ; Engl. hot. t. 277 ; Darlingt. fl. 

 Cest. p. 435 ; DC. prodr. 6. p. 578 ; Torr. <^ Gr. fl. N. Am. 2. p. 454. 



Annual. Stem 1-2 feet high, much branched. Leaves 2-4 inches long, hoary and 

 villous, particularly underneath ; the lower ones deeply toothed or pinnatiiid at the base. 

 Heads on terminal peduncles. Involucre closely imbricated ; the exterior scales ovate ; the 

 inner ones narrower. Flowers of the ray large and funnel-form, blue, or sometimes pale ; 

 those of the disk regular, usually purplish, with dark-colored anthers. Achenia with a pit or 

 areole on one side of the base. Pappus double, reddish, often unequal. 



Cultivated grounds, rubbish, etc. Introduced in a few localities, but hardly naturalized, 

 July - August. 



43. CNICUS. Vaill.; DC. prodr. G. p. 606. BLESSED THISTLE. 



[ From the Greek, knizo, to prick or wound.] 



Heads many-flowered ; the rays sterile, slender, nearly equal to the disk. Scales of the 

 involucre coriaceous, appressed, produced into a long rigid pinnated spinosc appendage. 

 Receptacle bristly. Achenia terete, smooth, strongly striate. Pappus triple ; the exterior 

 of 10 short teeth ; the intermediate of 10 elongated rigid bristles ; the inner of 10 short 

 bristles. — -An annual herb, sparsely clothed with a loose wool. Leaves clasping, somewhat 

 decurrent and pinnatifid. Heads terminal, bracteate. Flowers yellow. 



