484 



THE COMPOSITE FAMILY. 



Our garden Lettuces are luxuriant forms, produced by long culti- 

 vation of one or perhaps two southern species, which have not been 

 as yet satisfactorily identified, some botanists believing them to be cul- 

 tivated varieties of the prickly L. 



1. Wall Lettuce. Laetuca muralis, Eresen. (Fig. 580.) 



(Prenanthes, Eng. Bot. t. 457.) 



[ft A glabrous, erect annual or biennial, 



about 2 feet high, with slender branches, 



forming a loose, terminal panicle. Leaves 



few and thin, rather large, with a broadly 



triangular, toothed or lobed, terminal 



segment, and a few irregular smaller 



ones along the stalk ; the upper leaves 



, small, narrow, and entire or toothed. 



—\u/ Flower-heads small, on slender pedicels. 



<^P^ Involucres about 5 lines long, of 5 equal, 



^ linear bracts, with 1, 2, or 3 very small 



outer ones, containing 4 or 5 florets. 



Beak of the achenes much shorter than 



the achene itself. 



In woods and shrubby places, in Eu- 

 rope and Russian Asia, extending far 

 into the north, although not an Arctic 

 plant. Not uncommon in England, more 

 rare in southern Scotland, and only known 

 in Louth County in Ireland. Fl. summer. 



2. Prickly Lettuce. Laetuca Scariola, Linn. (Fig. 581.) 



(Eng. Bot. t. 268.) 



An erect, stiff annual or biennial, 2, 3, or even 4 feet high, of a more 

 or less glaucous green, with short but spreading branches, and quite 

 glabrous, except a few stiff bristles or small prickles on the edges or 

 on the midrib of the leaves. Leaves more or less spreading, varying 

 from lanceolate to broadly oblong, either bordered only with small 

 teeth, or with a few short lobes or coarse teeth usually curved down- 

 wards, or deeply pinnatifid with few narrow lobes ; the upper ones 

 narrow, more entire, and clasping the stem with pointed auricles. 

 Elower-heads in a more or less leafy panicle, sometimes long and 

 narrow, sometimes more branched and spreading. Involucres 4 or 5 

 lines long, of a few imbricate bracts, the short, broad, outer ones 



