wall lettuce USDA PLANTS Symbol: MYMU
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Mycelis muralis (L.) Dumort.

Jump to: Images | Distribution Maps | Sources
Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Synonym(s): wall-lettuce
Native Range: Europe, Turkey, Caucasus (GRIN);

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.
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.

Selected Images from Invasive.orgView All Images at Invasive.org


Plant(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Robert Vidéki, Doronicum Kft., Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Robert Vidéki, Doronicum Kft., Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Stem(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Stem(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Robert Vidéki, Doronicum Kft., Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.


Invasive Listing Sources:
Faith Campbell, 1998
Pacific Northwest Exotic Pest Plant Council, 1998