272 coMPOsiT.E. (cor:MrosiTK family.) 



Achcnia slender or spindle-shaped. P.ippus a single row of rather rijrid and 

 strongly roiighcncd-dcntienlatc bristles. — Perennial herbs, chiefly of inountiiins 

 and cold northern repons, witii simple .'■tcnis, bearing single or corymbed large 

 lieads and opposite leaves. Flowers yellow. (Name thought to be a corruption 

 of Ptaniiicu.) 



1. A. mollis, Hook. Soft-hairy; shm Icnf}/ (l°-2° high), bearing \ to 5 

 liciids ; leav(S thin, veiny, smoothish when old, toothed ; the upper ovale-hinceolntc, 

 closely sessile ; the lower narrower, tapering into a margined petiole ; scales of 

 the involucre pointed ; pappus almost plumose. — Alpine rivulets, mountains of 

 New Hampshire and N. New York, shores of Lake Superior, and northwest- 

 ward. July. 



2. A. nudicatllis, Ell. Hairy and rather glandular (1° -3° high); fcarcs 

 thirkish , ^-b-ntrced, ocatc or oblong, all sessile, mostly entire and near the root, 

 those of the naked stem small and only one or two pairs ; heads several, corymbed, 

 showy. — Damp pine barrens, S. Penn. and southward. April, May. 



65. CENTAUREA, L. Star-Thistle. 



Heads many-flowered ; the flowers all tubular, the marginal often much larger 

 and as it were radiate, sterile. Receptacle bristly. Involucre imbricated, the 

 scales margined or appendagcd. Achenia compressed. Pappus wanting, or of 

 a few bristles. — Herbs with alternate leaves and single heads. (Named from 

 the Centaur, Chiron.) 



1. C. CVaxus, L. (Bluebottle.) Scales of the globular involucre fringe- 

 margined ; false rnjjs large; pappus very short ; leaves linear, entire, or toothed at 

 the base; root annual. — Roadsides, escaped from gardens. July. — Flowers 

 blue, varying to purplish or white. (Adv. from Eu.) 



2. C. NIGRA, L. (Knapweed.) Scales of the globular involucre appcn- 

 diiged, and with a stiff black fringe; raijx- icanting ; pappus very short; leaves 

 lanceolate, or the lower lyrate-angied, rough ; root perennial. — Waste places, E. 

 New England. Aug. — Flowers purple. (Adv. from Eu.) 



3. C. CALcfTRAPA, L. (Star TiiiSTLE.) Stcm diflfuscly much branched ; 

 leaves pinnalely lohnl or spinulosc-toothed ; heads sessile, the middle scales of the. 

 ovoid involucre spiny; pappus none; flowers purple; root annual. — Norfolk, 

 Virginia, and Philadelphia. (Adv. from Eu.) 



66. CNICUS, Vaill. Blessed Thistle. 



Heads many-flowcrcd ; the ray-flowers tubular and sterile, shorter than the 

 rest, which arc all tubular and perfect. Scales of the ovoid involucre coriaceous, 

 apprcsscd, extended into a long and rigid pinnately spinose appendage. Re- 

 ceptacle clothed with capillary bristles. Achenia terete, short, strongly striate, 

 crowned with 10 short and horny teeth, and bearing a papi)us of 10 elongated 

 rigid bristles, and 10 short bristles alternate with the Inst in an inner row. —An 

 annual smoothish herb, with clasping scarcely i)iiinatilid-cut leaves and large 

 braeted heads. Flowers yellow. (Nmuic from kvI^co, to prid:) 



1. C. BENEDfcTLS, L. — Uoadsidus, Southward : rare, scarcely naturalized 

 (Adv. from Eu.) 



