Lactuca canadensis L.

Wild Lettuce

Lactuca_canadensis_plant.jpg
STATS

Native
CC = 3
CW = 3
MOC = 76

© SRTurner

Family - Asteraceae/Cichorieae

Stem - Erect, to 2 m, usually glabrous, often purple mottled. Latex tan or pale orange.

Lactuca_canadensis_stem.jpg Stem.

© SRTurner

Leaves - Extremely variable. Usually abundant on stem. Typically lanceolate to ovate, entire or pinnately lobed, often auriculate, sessile.

Lactuca_canadensis_leaves.jpg Leaves.

© SRTurner

Lactuca_canadensis_leaves2.jpg Leaves, abaxial view.

© SRTurner

Inflorescence - Highly branched, open panicles with numerous heads.

Lactuca_canadensis_inflorescence.jpg Inflorescence.

© SRTurner

Involucre - 8-10 mm long, cylindrical or urn-shaped, glabrous.

Lactuca_canadensis_involucre.jpg Involucre.

© SRTurner

Flowers - Ligulate florets 17-22, orange or tan-orange in color, with 4-7 mm pappus bristles.

Lactuca_canadensis_flowers.jpg Flowers.

© SRTurner

Fruits - 3-4 mm long, flattened and winged, nearly black, with beak shorter to same length as body of achene.

Lactuca_canadensis_fruits.jpg Fruits.

© SRTurner

Lactuca_canadensis_fruits2.jpg Fruiting pappus.

© SRTurner

Flowering - July - September.

Habitat - Prairies, forest openings, sand prairies, streambanks, pastures, etc.

Origin - Native to North America.

Other info. - This commonly encountered lettuce can be quite variable in appearance. The plant can be differentiated from other common lettuces by the presence of tan or orange latex; however, this character must be used in conjunction with other attibutes, since other species (e.g. L. hirsuta) also contain tan sap. Other key attributes include the dirty orange color of the flowering heads and a conspicuously leafy stem, though these characters are also variable.

Photographs taken at Faust County Park, St. Louis County, MO, 11-22-2010, near Dutzow, Warren County, MO, 8-6-2015, and at Sand Prairie Conservation Area, Scott County, MO, 8-12-2015 (SRTurner).