6. Lactuca Canadensis L. Wild Or Tall Lettuce. Wild Opium

Fig. 4073

Lactuca canadensis L. Sp. Pl. 796. 1753. Lactuca elongata Muhl.; Willd. Sp. Pl. 1525. 1804. Lactuca canadensis montana Britton, in Britton and Brown, 111. Fl. 3: 274. 1898.

Biennial or annual, glabrous throughout, somewhat glaucous; stem leafy up to the inflorescence, 3°-100 high, branching above into a narrow panicle. Leaves mostly sinuate-pinnatifid, those of the stem sessile or auriculate-clasping, 2'-8' long, the uppermost smaller, often lanceolate, acuminate and entire, sometimes all lanceolate and entire, the basal often 12' long, narrowed into petioles; heads numerous, 2"-3" broad; involucre cylindric, 4"-6" high, its outer bracts shorter than the inner; rays yellow; achenes oval, flat, about as long as the filiform beak; pappus white.

In moist, open places, Nova Scotia to British Columbia, Georgia, Alabama, Louisiana, Arkansas and Colorado. Santo Domingo. Trumpetweed, trumpet-milkweed, trumpets, and fire-weed. Butter- or horse-weed. Devil's-weed. Devil's-iron-weed. June-Nov.

Lactuca Morssii Robinson, with blue rays, and achenes 3 or 4 times longer than their filiform beaks, may be a hybrid with L. spicata.

6 Lactuca Canadensis L Wild Or Tall Lettuce Wild O 744

7. Lactuca Sagittifoha Ell. Arrow-Leaved Lettuce

Fig. 4074

L. sagittifolia Ell. Bot. S. C. & Ga. 2: 253. 1821-24. Lactuca integrifolia Bigel. Fl. Bost. Ed. 2, 287. 1824.

Not Nutt. 1818. L. elongata var. integ. T. & G. Fl. N. A. 2: 496. 1843.

Biennial; stem glabrous throughout, or hirsute below, leafy nearly up to the usually paniculate inflorescence, 2°-6° high. Leaves oblong, oblong-lanceolate or lanceolate, acuminate or acute, entire or denticulate, the lower rarely pinnatifid, sometimes spinulose on the margins, those of the stem sessile or sagittate-clasping, 3'-6' long, 1/2-1 1/2' wide, the basal and lower ones petioled; heads commonly very numerous, 2"-4" broad; involucre cylindric, 5"-7 ' high, the outer bracts shorter than the inner; rays yellow or reddish; achenes oval, flat, rather longer than their filiform beaks; pappus white.

In dry, open soil, New Brunswick and Ontario to Georgia, Idaho and Kansas. Called also devil's-iron-weed. July-Sept.

7 Lactuca Sagittifoha Ell Arrow Leaved Lettuce 7457 Lactuca Sagittifoha Ell Arrow Leaved Lettuce 746

8. Lactuca Pulchella (Pursh) Dc. Large-Flowered Blue Lettuce

Fig. 4075

Sonchus pulchellus Pursh, Fl. Am. Sept. 502. 1814. Lactuca integrifolia Nutt. Gen. 2: 124. 1818. Lactuca pulchella DC. Prodr. 7: 134. 1838.

Perennial, glabrous throughout, somewhat glaucous; stem rather slender, leafy up to the corymbose-paniculate inflorescence, 1°-3° high. Leaves linear-lanceolate, lanceolate or oblong, acute, entire, dentate, lobed or pinnatifid, those of the stem sessile or partly clasping, 2'-8' long; 2"-18" wide, the lowest and basal ones sometimes petioled; heads mostly numerous, 6"-10" broad; branches and peduncles scaly; involucre well imbricated, 8"-10" high, its outer bracts successively shorter, ovate-lanceolate; rays bright blue or violet; achenes oblong-lanceolate, flat, twice as long as their tapering beaks; pappus white.

In moist soil, western Ontario to British Columbia, Michigan, Iowa, Kansas, New Mexico and California. June-Sept.

Lactuca campestris Greene, of the prairie region, is described as differing from this by yellow rays.