Kansas Wildflowers and Grasses

WILD LETTUCE

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Lactuca canadensis L.

Wildcat Glades Conservation & Audubon Center, Newton County, Missouri

Biennial

Height: 20-120+ inches

Family: Asteraceae - Sunflower Family

Flowering Period: July, August, September

Also Called:

Canada wild lettuce, tall lettuce.

Stems:

Erect, solitary, multi-branched above, glabrous or rarely coarsely-hairy, somewhat waxy, often purple-spotted; latex brown.

Leaves:

Alternate, highly variable, sessile; basal and lower stem leaves sickle-shaped to linear-ovate or egg-shaped, 6 to 14 inches long, 1.6 to 5.6 inch wide; margins weakly toothed or pinnately-cleft to deeply pinnate-lobed; lower midrib often stiff-hairy; middle and upper stem leaves linear-ovate, egg-shaped, or lanceolate, 4 to 12 inches long; margins entire or toothed to pinnate-lobed; lower midrib glabrous; upper leaves gradually reduced.

Inflorescences:

Panicle, much-branched, diffuse, cone-shaped, terminal; heads 50-100+, small, cylindric, less than 1/2 inch across, 1/3 to 1/2 inch tall; bracts 17, overlapping, about 1/3 inch long at flowering and 1/2 inch long in fruit, usually bent downward in fruit; outer bracts lanceolate, inner bracts linear.

Flowers:

Ray florets 15-22, about 1/6 inch long, yellow, pinkish-orange, or reddish apex and yellow base; anthers yellow, protruding; disk florets absent.

Fruits:

Achene, elliptic or oblong, flattened, 1/5 to 1/4 inch long (including thread-like beak), 1/12 inch wide, dark brown, prominent lateral wings, single rib on upper and lower surfaces, tipped with white bristles 1/5 to 1/4 inch long.

Habitat:

Woodland margins and clearings, stream and river banks, rocky open woods, waste places, roadsides, margins of lakes and ponds, thickets, marshes, pastures, borders of fields, disturbed sites; moist, sandy soils.

Distribution:

Principally in the east 1/2 of Kansas.

Origin:

Native

Toxicity:

When grazed, the plant can cause milk to be tainted.

Uses:

Native Americans would steep the roots and bark and take the tea for back and kidney pains; took a tea to induce sleep; applied a poultice of pulverized roots to stop bleeding cuts; and used the milky latex to treat poison ivy sores. The leaves were cooked and eaten as greens.

Wild lettuce