404 COMPOSITA LACTUCA 
£ ONCHUS 
L. scarroua, L. Sp. ed. 2 1119. Biennial: glabrous throughout or hir- 
sute at the base; green and glaucous: stem stout, 2-7 feet high, leafy, usu- 
ally paniculately branched: leaves lanceolate to oblong, with spinulose- 
denticulate margins, sometimes sinuate.toothed or pinnatifid, sessile or 
auriculate-clasping, midrib below beset with weak prickles: heads small, 
6-12-flowered, very numerous, in an — panicle: corollas pale yellow: 
achenes obovate-oblong, several-nerved, margined, about as long as the 
filiform beak. Becoming comuion in fields and waste places. Introduced 
from Europe. 
L. sativa The common Letruce is common along the Rail Road in the 
southern part of Oregon but is hardly naturalized. 
L. Canadensis L. Sp. ii, 796. Biennial or annual; glabrous and 
glaucescent: stem strict, 4-12 feet high, very leafy up to the elongated 
narrow panicle: leaves mostly sinuate-pinnatifid, 6-12 inches long, with 
margins entire or sparingly dentate, and midrib naked or rarely some 
sparse bristles, most of the cauline partly clasping by a sagittate or auricu- 
late base: involucre half-inch or less high, 12-20-flowered: flowers yellow. 
achenes blackish, obscurely scabrous-rugulose, lightly 1-neryed on the 
middle of each face, broadly oval, with distinct thin margins, rather long- 
er than the beak: pappus white. Moist woods, Oregon and Washington 
to the Eastern States. : 
L. sagittifolia Ell. Bot 8S. C. & Ga ii, 253. Glabrous; 3-6 feet high, 
leafy nearly to the usually loosely paniculate inflorescence: leaves oblong 
to lanceolate, 3-10 inches long, acute or acuminate, entire or denticulate, 
the lower sometimes pinnatifid, whitish beneath, midrib naked : involucre 
5-7 lines high: flowers pale yellow or purplish : achenes oval, thin-margined 
longer than the beak. Open ground, Idaho to the Eastern States. 
§ 2 Lacrucastrum Gray Syn. Fl. i, pt, 2, 448. Root perennial. 
Involucre well imbricated. Achenes lanceolate-oblong, flat, not 
margined, tapering into a beak not longer than the breadth of the 
body. 3 
L. pulehella DC. Prodr. vii, 134. Very glabrous: stems 1-5 feet high. 
leafy up to the open corymbiform panicle: leaves from linear-lanceolate to 
narrowly oblong, entire or runcinate-dentate, or some lower ones pinnati- 
fid ; cauline sessile but not auriculate at base: branches of the loose panicle 
scaly : involucre 8 lines high, 12—-15-flowered, its outer bracts ovate-lanceo- 
late: flowers bright blue or violet-purple: achenes barely 2 lines long, 
striate-nerved, the tip of the short beak soft and usually whitish. Alluvial 
ground, Oregon to Brit, Columbia, Hudson Bay and Michigan. | 
§ 8 Muteepium Gray l.c. Biennial or perennial herbs with 
usually bluish flowers, Achenes thickish, oblong, with some 
strong ribs and nerves: contracted at summit into a short stout 
beak, or into a mere neck under the dilated apex. 
L. spicata Hitche. L. leucophea Gray. Stem usually stout, 3-12 
feet high, leafy up to the panicle: leaves 3-12 inches long by 2-6 broad, 
sinuately or runcinately pinnatifid, coarsely and irregularly or doubly den- 
tate; upper cauline sessile by a mostly narrow but auriculate or partly 
clasping base: heads in a pyramidal crowded panicle: involucre oblong, 5 
lines high: flowers bluish: achenes narrowed at summit to a short but 
manifest neck. Moist ground, Oregon to Brit. Columbia and the E, States. 
118 SONCHUS Tourn. L. Gen. n. 908. 
Succulent herbs with leafy stems, alternate spinulosely or cili- 
ee es ee ed 
