468 SYNGENESIA— POL.-FRUSTRAN. Centaurea. 



4. C. Scabiosa. Greater Knapweed. 



Calyx-scales ovate, fringed, somewhat downy. Leaves pin- 

 natifid ; segments lanceolate, roughish, partly toothed. 



C. Scabiosa. Linu.Sp. PL 1291. Willd. v. 3.2296. Fl. Br. 9\l. 

 Engl. Bot. V. 1 . <. 56. Hook. Scot. 249. 



Cyanus n. 186. Hall. Hist. v. 1.81. 



Jacea major. Rail Syn. 198. Ger. Em. 727./. 



J. nigra laciniata. Moris, v. 3. 140. sect 7. t.2S.f. 10. 



Scabiosa major. Matth. Valgr. v.2. olS.f. Camer. Epit.7\0.f. 

 Dalech. Hist. 1066./. 



Matfellon. Petiv. H. Brit. t. 22. f. 7. 



In the borders and ridges of corn fields, and by way sides, common. 



Perennial. July, August. 



Root rather woody. Stem about 2 feet high, erect, branched, an- 

 gular, furrowed, leafy, smooth to the touch. Leaves dark green, 

 slightly hairy on both sides, rough-edged, deeply and very vari- 

 ously pinnatifid, the segments acute, unequal, sometimes ovate, 

 sometimes lanceolate, and in the latter case more toothed or 

 sharply serrated. Fl. terminal, stalked, solitary, large and hand- 

 some, crimson, rarely white j their radiant J?07eis large, each 

 with 5 deep, long and narrow segments. Calyx-scales green 

 and somewhat downy in their lower half, black and triangular 

 above, fringed with fine parallel teeth, or bristles pale at the 

 ends. Seeds crowned with many reddish bristles. The calyx 

 becomes reflexed after the seeds are blown away, and is render- 

 ed conspicuous by the shining silvery hue of its inside. 



A variety was gathered on dry banks, near the sea coast of An- 

 gus-shire by the late Mr. G. Don, which he thought distinct, 

 and took for C intybacea of Lamarck and DeCandolle. It has 

 deeply and narrowly divided foliage, the radical leaves being 

 interruptedly pinnate, but has no specific mark. Another va- 



. riety as I presume, on the authority of Dr. Hooker, gathered in 

 Scotland by Mr. David Don, has the leaves less deeply divided ^ 

 the radical ones very large. This was taken by its discoverer 



• for C. coriacea, M^illd. Sp. PI. v. 3. 2296, which it may probably 

 be, as Willdenow says the latter is but too near akin to C. Sca- 

 biosa. Several exotic species of Centaurea may be observed to 

 vary extremely in the breadth and subdivision of their leaves. 



** Calyx-scales palmate and spinous. 



6. C. Isnardi. Jersey Star-thistle. 



Calyx-scales vvith palmate spines. Leaves toothed, some- 

 what lyi'ate, roughish, slightly clasping the stem. Flow- 

 ers terminal, solitary ; leafy at the base. 



C. Isnardi. Linn. Sp. PI. \295. Willd. v. 3. 23\2. Fl. Br.9\2. 

 Engl. Bot. V. 32. t. 2256. Dicks. H. Sicc.fasc. 16. 10. Hull 

 ed. 2. V. 1 . 247. 



