Tall Lettuce

Appearance

Annual biennial dicot that may appear to be a weedy plant, but is variable in appearance. Typically it is 7.6 cm-20.3 cm tall, but may be found up to 25.4 cm and 7.6 cm across with an oblong shape, wider at bases, and come to point at tip.

Stem is glabrous and often glaucous, with light or reddish green color. Leaves are alternate mostly with deep pinnate lobes, however, small leaves have shallow lobes or none at all. Leaf surface color ranges from shiny to dull in light to dark green pigments that sometimes may appear in purple or yellow shear cast. Leaves are slightly toothed along margins with small hairs along underside of leaf vein.

Flower heads appear dandelion-like, attach at the apex of the stem, and are 8mm across. The florets are yellowish or slightly red to orange in color, consisting of 12-25 per plant. The base of the flower head has several floral bracts that appear light green and glabrous.

Flowers bloom in late summer or early fall for approximately 3–4 weeks. The flower does not seem to emit noticeable scent. After the blooming period, flowers are replaced by dark achenes with tufts of white hair. Its achene has a longitudinal ridge, may have black spots on either side, and are distributed by the wind. They are ovoid; slightly flattened, but curved in shape. A plant may have buds, flowers, and achenes simultaneously. Roots are a thick deep taproots that contain a white latex that is apparent when cut.

Habitat

It occurs across the continental United States, except for Nevada and Arizona, and across most provinces in Canada. It is found commonly in all counties in Illinois.

It grows in moist to dry habitats in a variety of soil types, include black soil, clay, and gravel prairies. ''Lactuca canadensis'' can be found in woodlands, thickets, savannas, borders of lakes and rivers, limestone glades, fence rows, pastures, abandoned fields, powerline clearances, road and railroad sides, vacant lots, and waste areas. It is most common in degraded and disturbed habitats, but also may be found in rich and diverse, high-quality habitats.

Uses

''Lactuca canadensis'' contains lactucarium, which is the milky sap that flows through stem, leaves, and roots of the plant. It is used as a medicinal herb when dried after contact with air. A survivalist publication, ''The Lost Ways'', states that its fresh leaves may be use to create a solution that may act as an analgesic and may be stored for later use. It may be used as medicinal treatments for its anodyne, antispasmodic, digestive, diuretic, hypnotic, narcotic, and sedative properties. Concentrations of lactucarium are low in young plants, but increase in older plants, occurring highest when in blooming period. Sap may be applied to skin in use for treatment of external warts. It has been seen as valuable in treatment as a remedy for insomnia and muscular arthritis. It is a relaxing and sedative herb that is used to induce sleepiness, and to calm restlessness and anxiety.

Plant has not been seen to be toxic, however some plants in the genus contain a narcotic principle that has its highest concentration when in the blooming period. Young leaves and stems may be edible and cooked and eaten as greens.