Lactuca.] XLIII. COMPOSITE. 261 



Panicle almost reduced to a long, clustered spike. Flowers yellow. 



Beak about twice the length of the achene 3. L. saligna. 



Leaves pinnatifid, with a triangular terminal lobe. Flowers blue. 



Beak 4. L. alpina. 



Our garden Lettuces are luxuriant forms, produced by long cultivation 

 of one or perhaps two southern species, which are not satisfactorily 

 identified, some botanists believing them to be cultivated states of 

 L. Scariola. 



1. L. muralis, Fresen. (fig. 588). Wall L. — A glabrous, erect annual 

 or biennial, about 2 feet high, with slender branches, forming a loose, 

 terminal panicle. Leaves few and thin, with a broadly triangular, 

 toothed or lobed, terminal segment, and a few irregular smaller ones 

 along the stalk; the upper leaves narrow, entire or toothed, clasping 

 the stem with prominent auricles. Flower-heads small, on slender 

 pedicels. 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 Europe and Kussian Asia, extending 

 far into the north, although not an Arctic plant. Not uncommon in 

 England, Perth and Stirling in Scotland, and only known in Wicklow 

 and Louth in Ireland. Fl. summer. 



2. L. Scariola, Linn. (fig. 589). Prickly L. — 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, but often twisted so as to be 

 vertical instead of horizontal, varying from lanceolate to broadly oblong, 

 either bordered only with small teeth, or with a few short lobes or 

 coarse teeth usually curved downwards, or deeply pinnatifid with few 

 narrow lobes ; the upper ones narrow, more entire, and clasping the 

 stem with pointed auricles. Flower-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 passing gradually into the inner, long, narrow 

 ones. Florets 6 to 10 or 12, of a pale yellow. Achenes much flattened, 

 obovate-oblong, striated, varying in colour from nearly white to nearly 

 black, with a slender beak about the length of the achene. 



In dry or stony wastes, on banks and roadsides, in central and southern 

 Europe, extending over a great part of central Asia. Thinly scattered 

 in Britain, from southern England to the low tracts in the south-east 

 Highlands of Scotland. Fl. summer. The name of L. Scariola is often 

 limited to the varieties with more erect leaves, with deeper and narrower 

 lobes ; and those with broader leaves, toothed only, and not so glaucous, 

 have been considered as a distinct species, under the name of L. virosa, 

 Linn. 



3. L. saligna, Linn. (fig. 590). Willow L.— Very near L. Scariola, 

 but more slender and twiggy ; the leaves upright against the stem, and 

 narrower ; the stiff panicles with branches so short that the flower- 

 heads appear clustered in a simple spike ; and the beak of the achene 

 from twice to three times its own length. These characters are, however, 

 so variable as to occasion some doubt whether the two species are really 

 distinct. 



