282 COMPOSITE. (COMPOSITE FAMILY.) 



2. A. nudicaillis, Ell. Hairy and rather glandular (l-3high); 

 leaves thickish, 3 - 5-nerved, ovate or oblong, all sessile, mostly entire ; those of the 

 naked stem small and only 1 or 2 pairs ; heads several, corymbed, showy. 

 Damp pine barrens, Virginia and southward. April, May. 



65. CENT A UREA, L. STAR-THISTLE. 



Heads many-flowered ; the flowers all tubular, the marginal mostly falsely 

 radiate and larger, sterile. Receptacle bristly. Involucre imbricated, the scales 

 margined or appendaged. Achenia compressed. Pappus wanting, or of a few 

 bristles. Herbs with alternate leaves and single heads. (Named from the 

 Centaur, Chiron.) 



1. C. CYANUS, L. (BLUEBOTTLE.) Scales of the globular involucre 

 fringe-margined ; false rays large, pappus very short ; leaves linear, entire, or 

 toothed at the base. (J) Road-sides, escaped from gardens. July. Flowers 

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



2. C. NIGRA, L. (KNAPWEED.) Scales of the globular involucre appen- 

 daged, and with a stiff black fringe; rays wanting; p:ippus verv short; leaves 

 lanceolate, or the lower lyrate-angled, rough. 1J. Waste places, E. New Eng- 

 land. Aug. Flowers. purple. (Adv. from Eu.) 



3. C. CALCfTRAPA, L. (STAR THISTLE.) Stem diffusely much branched ; 

 leaves pinnately lobed or spinulose-toothed ; heads sessile, the middle scales of tfie 

 ovoid involucre spiny; pappus none; flowers purple. (J) Norfolk, Virginia. 

 (Adv. from Eu.) 



C. AMERICANA, Nutt., a showy species of the Southwestern States, the 

 only one which belongs to this country, is cultivated in gardens. 



66. C NIC US, Vaill. BLESSED THISTLE. 



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

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

 appressed, extended into a long and rigid pinnately spinosc appendage. Re- 

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

 crowned with 10 short and horny teeth, and bearing a pappus of 10 elongated 

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

 annual smoothish herb, with clasping scarcely pinnatifid-cut leaves and largo 

 bracted heads. Flowers yellow. (Name from Ki/t^w, to prick.) 



1. C. BENEDfCTUS, L. Road-sides ; scarcely naturalized. (Adv. from Eu.) 



67. CIRSIUM, Tourn. COMMON or PLUMED THISTLE. 



Heads many-flowered ; the flowers all tubular, perfect and similar, or rarely 

 imperfectly dioecious. Scales of the ovoid or spherical involucre imbricated in 

 many rows, tipped with a point or prickle. Receptacle thickly clothed with 

 soft bristles or hairs. Achenia oblong, flattish, not ribbed. Pappus of numer- 

 ous bristles united into a ring at the base, plumose to the middle, deciduous 



