Bidens.] SYNGENESIA — iEgUALIS. 299 



pubescent cottony beneath, flowers mostly solitary. — Carduus, 

 Htids. — E. Bot. t. Ml. 



Low wet pastures. Rare in Scotland ; Isla and Arran. Fl. July. 1/ . 

 — About 1 foot high. Leaves waved, toothed and spin}'. Flowers 

 solitary. Scales of the involucre with short spines, lanceolate, closely 

 imbricated, cobwebbed. 



9. C. acdulis, Willd. (dwarf Plume-thistle); stemless, invo- 

 lucre glabrous. — Carduus, L.—E. Bot. t. 161. 



Frequent and destructive in dry gravelly or chalky pastures, in some 

 parts of England ; as Dorsetshire and Norfolk. Rare in Scotland. Fl. 

 in\y. If. — Leaves spreading close to the ground, oblong, pinnatlfid, seg- 

 ments lobed and spinous, glabrous. From the centre of these leaves arises 

 one sessile, purple Jiower. Livolucre obovato-cylindrical, imbricated 

 with close, appressed, lanceolate, acute, greenish scales, not spinous. 



20. ONOP6RDU3r. Linn. Cotton-thistle. 



1. O. Acdfithiiim, L. (^common Cotton-thistle) ; scales of the 

 involucre spreading subulate, leaves ovato-oblong sinuated and 

 spinous decurrent woolly on both sides. E. Bot. t. 977. 



Waste-ground, road-sides, &c. in a gravelly soil. Less frequent in 

 Scotland. Fl. Aug. $ . — ^Four to 6 feet high, branched and winged at 

 the summit ; wings very spinous. Involucre globose. Flowers Y>\xvY>\e. 

 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. 



21. Carlina. Linii. Carline-thistle. 



1. C. vidgdris, L. (common Carline-thistle) ; stem many- 

 flowered corymbose pubescent, leaves lanceolate unequally spin- 

 ous and sinuated downy beneath. E. Bot. t. 1144. 



Dry hilly pastures, and fields. Rare in the West of Scotland ; Ben- 

 nanhead. Isle of Arran. Fl. June. $ . — 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, membran- 

 ous, yellow, entire, spreading and forming an horizontal ray around the 

 purplish j?ore^5. Anthers with 2 bristles at the base. 



22. Bidens. Linn. Bur-marigold. 



1. B. cernua, L. {imdding Bur-marigold) ; flowers drooping, 

 bracteas lanceolate entire (longer than the involucre), leaves 

 lanceolate serrated undivided, bristles of the fruit about 3 erect. 

 E. Bot. t. 1114. 



Sides of rivulets, ditches and lakes, frequent, Fl. June — Aug. . 

 — 1 — 2 ft. and more high, branched and slightly hispid. Leaves gla- 

 brous, deeply serrated. Flowers large, greenish-yellow. 



2. B. tripartita, L. (trijid Bur-marigold) ; leaves tripartite, 

 leaflets lanceolate deeply serrated, bristles of the fruit 2 — 3. E. 

 Bot. t. 113. 



Marshy places, sides of ponds and lakes. Fl. July. Q • — Readily 

 distinguished by its divided leaves. The flowers, which are slightly 

 drooping, are smaller than those of B, cernua. 



