Wall-lettuce

Mycelis muralis

Invader Images

    • Wall Lettuce
      Wall Lettuce
    • Wall Lettuce Flower
      Wall Lettuce Flower
    • Wall Lettuce Infestation
      Wall Lettuce Infestation

Identification

Appearance

Mycelis muralis is a slender, glabrous, herbaceous plant. It is annual to biennial depending on the habitat. Stems are erect, 2-3 ft. (0.6-0.9 m) tall, branched above and may one or more stems from a fibrous root. The stem surface is glabrous, often glaucous, and exudes milky juice when broken.

Foliage

Basal and lower stem leaves are 2.5-7 in. (6.4-17.8 cm) long, 1-3 in. (2.5-7.6 cm) wide, glabrous and deeply lobed, with broad, terminal segments. Leaf base is auriculate (lobed). The few middle and upper stem leaves are reduced in size.

Flowers

Each flower head is comprised of 5 yellow, strap-shaped ray florets.

Fruit

Achenes are approximately 0.13 in. (0.33 cm) long, several-nerved, and black or brown with white pappus that may disperse seeds long distances by wind.

Biology

This is considered a watch list species

Origin

Native to Eurasia

Habitat

Grows in disturbed habitats, meadows, and fields.

Ecological Threat

Mycelis muralis reproduces exclusively by seed. A plant may produce up to 500 seeds in shaded sites and up to 11,500 seeds in open sites. Wall lettuce can grow in deep shade and full sun. It is adapted to a range of soil conditions. It readily invades disturbed habitats.

Management Options

**Be careful not to damage or kill nearby native plants when conducting management work. And when using herbicides, always follow the instructions on the label.**

Citations

Photo Credit

5450699, 5450682, 5450662, Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Information Credit 

Go Botany

Bugwood