266 SUMMER FLOWERS. 



prickly ; flower-heads hemispherical, 3-4 in a small terminal 

 corymbj the outer involucral bracts broadly lanceolate, bor- 

 dered with very prickly teeth or lobes, the inner one« linear, 

 entire, with smooth and shining, horizontally-spreading tips. 

 — Dry, hilly pastures and fields. Fl. July to September. 



(160) Carduus. Thistle. 



* JPappus of simple hairs. 



C. nutans : biennial ; stems erect, cottony, 2-3 feet high ; 

 leaves deeply pinnatifid, very prickly, their edges decurrent 

 along the stem, forming narrow very prickly wings ; flower- 

 heads, large and drooping, crimson, solitary or 3-4 in a loose 

 corymb; involucral bracts numerous, with a stifl", narrow- 

 lanceolate appendage, ending in a spreading prickle. — Musk 

 Thistle. — Waste places. Fl. July, August. 



C. acanthoid.es much resembles this, but is usually taller 

 and rather more branched; the leaves narrower and more 

 prickly ; the stem more thickly covered with prickly append- 

 ages, decurrent from the base of the leaves ; the flower-heads 

 smaller, globular, drooping; and the numerous narrow in- 

 volucral bracts ending in a linear, spreading prickle. 



** Pappus of feathery hairs. 

 t Leaves decurrent, forming prichly wings to the stem. 



C. lanceolatus ; biennial ; stems stout, 3-4 feet high, winged 

 and prickly ; leaves waved pinnatifid, with short narrow lobes, 

 the terminal one longer and lanceolate, all ending in a stifi" 

 prickle, rough above, with short almost prickly hairs, white 

 and cottony beneath ; flower-heads few, ovoid, the involucnJ 

 bracts lanceolate, cottony, ending in a stiff", spreading prickle ; 

 florets purple. — Fields, pastures, and waste places. Fl. June 

 to September. 



