Centaurea.~\ xlvi. composite: cynarocephala:. 239 
21. Onopordum Linn. Cotton-thistle. 
Achenes 4-ribbed, glabrous. Pappus pilose, rough, sessile, 
united into a ring at the base and deciduous. Receptacle 
honey-combed. Involucre tumid, imbricated, the scales spread- 
ing and spinose. Anthers with subulate appendages at the 
apex, shortly caudate at the base. — Name: ovoq, an ass, and 
7rti)Cii>, to crepitate ; from the effect, according to Pliny, upon the 
ass which eats it. 
1. O. Ac&nthium L. ( common C.)'; scales of the involucre 
spreading subulate, leaves elliptic-oblong sinuate spinous 
decurrent woolly on both sides. E. B. t. 977. 
Waste-ground, road-sides, &c., in a gravelly soil. Less frequent 
in Scotland. $ . 8 . — Stem 4 — 6 feet high, branched and winged at 
the summit ; wings very spinous. Involucre globose. Flowers purple. 
The seeds of this and of others of the Thistle tribe are much eaten 
by birds. It is cultivated in Scotland as the Scotch thistle. 
22. Carlina Linn. Carline-thistle. 
Achenes oblong, cylindrical, silky. Pappus feathery, sessile, 
hairs unequally united at the base. Receptacle chaffy, scales irre- 
gularly cleft. Involucre imbricate, tumid; the outer scales lax 
with numerous spines; the inner coloured, spreading resembling 
a ray. Anthers with ciliate bristles at the base, and long 
appendages at the apex. — Name: the same as Carolina-, from 
a tradition that the root was shown by an angel to Charlemagne 
as a remedy for the plague which prevailed in his army. 
1. C. vulgaris L. ( common C.) ; stem many-flowered corym- 
bose pubescent, leaves lanceolate unequally spinous and sinuate 
downy beneath. E. B. t. 1144. 
Dry hilly pastures, and fields. Rare in the west of Scotland ; 
Galloway; Bennan-head, Isle of Arran. $. 6 — 10. — One foot 
high, very spinous, but the spines generally short. Ext. scales or 
leaflets of the involucre much resembling the leaves , but smaller ; inner 
ones linear, membranous, yellow, entire, spreading and forming a 
horizontal ray around the purplish florets. Anthers with two bristles 
at the base. 
[Of C. racemosa a single specimen was found in the Isle of Arran, 
Galway Bay, Ireland, by Mr. Andrews ; but truly indigenous species 
do not occur in an isolated manner, unless where expelled by cultiva- 
tion.] 
23. Centaurea Linn. Knapweed, Blue-bottle, and Star- 
thistle. (Tab. IV. B.) 
Achenes compressed. Pappus pilose or scaly or none, rarely 
exceeding the achene in length. Receptacle bristly. Involucre 
imbricate. Florets of the disk perfect ; of the circumference 
narrow, funnel-shaped, irregular, without stamens or pistil 
