COMPOSITE. 



483 



In open pastures, andmeadows, widely- 

 spread over Europe and Russian Asia, 

 chiefly in mountain districts, although 

 not an Arctic plant. Bare in Britain, 

 the only reliable localities being in Suf- 

 folk, Cambridgeshire, and North Wales. 

 FL summer. 



Fig. 579. 



XXXIII. LETTUCE. LACTUCA. 



Annual or perennial herbs, glabrous or with a few stiff bristles ; the 

 stems leafy, erect, and branched, with (in the British species) nume- 

 rous small heads of yellow flowers. Involucre narrow, of a few im- 

 bricated bracts, containing very few florets. Achenes flattened, taper- 

 ing into a slender beak, with a pappus of numerous white and silky, 

 simple hairs. 



A genus widely spread over southern Europe and central Asia, and 

 among the exotic species includes several species differing from the 

 British ones in their large blue flowers. It has the flattened achenes 

 of Sowtliistle, from which the only positive distinctive character is the 

 beak of the achenes, but the narrow involucres and few florets generally 

 give it a different habit. 



Leaves thin, on long stalks, with a broad terminal lobe. Panicle 



slender. Beak shorter than the achene itself . . . . 1. Wall L. 

 Leaves mostly sessile, rather stiff, often prickly. Panicle rigid. 

 Beak as long as or longer than the achene. 

 Panicle rather loose, oblong or spreading. Beak about the 



length of the achene 2. PricTcly L. 



Panicle almost reduced to a long, clustered spike. Beak about 



twice the length of the achene . 3. Willow L. 



2p2 



