304 COMPOSITE, (composite family.; 



pas, its bristles falling separately. — Leafy -stemmed herbs, with panicled heads , 

 flowers of variable color, produced in summer and autumn. ( rhe ancient 

 name of the Lettuce, L. saliva ; from lac, milk, in allusion to the milky juice.) 



§ 1. SCARIOLA. Ackenes i^ery JJat, orbicular to oblong, l-nerv( d on each face, 

 with ajiliform beak; biennial or annual ; cauline eaves sagittate-clasping. 



L. ScARiOLA, L. (Prickly Lettuce.) Stem below sparsely prickly- 

 bristly, as also the midrib on the lower face of the cbloug or lanceolate spinu- 

 lose-denticulate vertical leaves; panicle narrow ; heads small, 6- 12-flowered; 

 achenes striate. — Waste grounds and roadsides, A tlantic States to Mo. and 

 Minn. (Adv. from Eu.) 



1. L. Canadensis, L. (Wild Lettuce.) Mostly tall (4-9° high), 

 very leafy, smooth or nearly so, glaucous; leaves ()-12' long, pale beneath, 

 mostly sinuate-pinnatifid, the upper lanceolate and entire (rarely all but the 

 lower narrow and entire) ; heads about 20-flowered 3 - 6" long, numerous, in 

 long and narrow or diffuse panicles ; flowers pale vellow ; achene oval, rather 

 longer than the beak. — Rich damp soil, borders of ields or thickets ; common. 



2. L. integrifblia, Bigel. Less leafy, 3-^° high, loosely branched 

 above or heads loosely panicled; leaves undivided, oblong-lanceolate, pointed, 

 denticulate or entire ; flowers yellow or purplish. (L. Canadens.s, var. integ- 

 rifolia, Torr. tV Graij.) — N. Eng. to 111., and southward. 



3. L. hirsuta, Muhl. Rather few-leaved, 2 - 3° high, comn lonly hirsute 

 at base ; leaves hirsute both sides or only on the midrib, mostly runcinate-pin- 

 natifid; heads in a loose open panicle; achenes oblong-oval, about as long as 

 the beak; flowers yellow-purple, rarely whitish. (L. Canadensis, var. san- 

 guinea, Torr. S^^ Gray.) — E. Mass. to Minn., and southward. 



4. L. Ludoviciana, DC. Glabrous, leafy, -2-5° high; leaves oblong, 

 sinuate-pinnatifid and spinulosely dentate, ciliate ; heads in an oj>en panicle; 

 involucre more imbricate ; flowers yellow. — Minn , Iowa, and south west ward. 



§ 2. LACTUCASTRUM. Achenes flat, lanceolate-oblong, taperinc to a short 

 slender beak ; perennial ; flowes blue. 



5. L. pulch^Ua, DC. Pale or glaucous; stem simple, 1-2° high; 

 leaves sessile, oblong- or linear-lanceolate, entire, or the lower ruiicinate-pin 

 natifid; heads few and large, racemose, erect on soaly-bracted peduncles; in 

 volucral scales imbricated in 3 or 4 ranks. (Mulgedium, Nutt.) — U pper Mich, 

 to Minn. ; common on the plains westward. 



§ 3. MULGEDIUM. Achenes thickish, oblong, contracted into a thort thick 

 beak or neck ; annual or biennial ; flowers chiefly blue. 



6. L. acuminata, Gray. Tall biennial (3-7° high), with many small 

 heads in a loose panicle, on diverging peduncles; leaves ovate to oMong-lan- 

 ceolate, pointed, sharply and sometimes doubly serrate, sometimes hairy on 

 the midrib beneath, contracted into a winged petiole, the lowest occasionally 

 sinuate or cleft at base, and the cauline sagittate or hastate ; achenes beak- 

 less; pappus white. (Mulgedium, DC.) — Bordei's of woods, N. \. to 111. 

 and Fla. 



7. L. Florid^na, Gaertn. Leaves all lyrate or runcinate, the upper 

 often with a heart-shaped clasping base; panicle larger; achenes distinctly 

 beaked; otherwise as n. 6. — Rich soil, Penn. to lU., and southward. 



