tall blue lettuce - Species Profile
Conservation • Wetland • Description • Habitat • Ecology • Use • Distribution • Taxonomy
Conservation Status
IUCN Red List
not listed
NatureServe
NNR - Unranked
SNR - Unranked
Minnesota
not listed
Wetland Indicator Status
Great Plains
FAC - Facultative
Midwest
FAC - Facultative
Northcentral & Northeast
FAC - Facultative
Description
Tall blue lettuce is a 2′ to 6½′ tall, erect, annual or biennial forb with a thick, deep taproot. The stems and leaves contain a milky latex.
The stems are leafy and hairless.
The alternate leaves are lobed halfway or more to the midrib but not reaching the midrib. They are up to 4″ to 16″ long and 1½″ to 8″ wide. They are attached to the stem without a leaf stalk, with the base partly surrounding the stem (clasping). The main veins on the underside are hairy.
The inflorescence is a terminal tall, narrow, crowded cluster, and small clusters in the leaf axils.
The flower heads are about ⅜″ across and have 15 to 50, usually 20 to 30, bluish to white ray florets.
The fruit is a brown achene with fluffy, grayish-brown bristles attached to the tip.
Height
2′ to 6½′
Flower Color
Bluish to white
Similar Species
Canada lettuce (Lactuca canadensis) has yellow flowers.
Prickly lettuce (Lactuca serriola) has yellow flowers. The leaves have prickles on the leaf margins and on the underside of the midvein.
Blue lettuce (Lactuca pulchella) has large, showy flower heads that measure, ¾″ across. The achene has white bristles attached to the tip.
Woodland lettuce (Lactuca floridana var. floridana) has a more open inflorescence and tends to be less leafy than tall blue lettuce. The flower heads have 10 to 15 ray florets. The achene has white bristles attached to the tip. Its range extends into only the lower third of Minnesota.
Habitat
Moist. Thickets, stream banks, woods.
Ecology
Flowering
July to September
Pests and Diseases
Use
Distribution
Sources
Biodiversity occurrence data published by: Minnesota Biodiversity Atlas (accessed through the Minnesota Biodiversity Atlas Portal, bellatlas.umn.edu. Accessed 1/3/2023).
Midwest Herbaria Portal. 2026. https://midwestherbaria.org/portal/index.php. Accessed 1/3/2023.
Lactuca biennis (Moench) Fernald in GBIF Secretariat (2023). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org. Accessed 1/3/2023.
Nativity
Native
Occurrence
Common
Taxonomy
Kingdom
Subkingdom
Pteridobiotina
Phylum
Tracheophyta (Vascular Plants)
Class
Order
Asterales (Sunflowers, Bellflowers, Fanflowers, and Allies)
Family
Asteraceae (Sunflowers, Daisies, Asters, and Allies)
Subfamily
Cichorioideae (Chicories, Dandelions, and Allies)
Tribe
Cichorieae (Lettuce, Chicory, Dandelion, and Salsify)
Subtribe
Lactucinae (Lettuce)
Genus
Lactuca (Wild Lettuces)
Subordinate Taxa
Synonyms
Agathyrsus floridanus
Cicerbita canadensis var. integrifolia
Cicerbita spicata
Cicerbita spicata var. integrifolia
Cicerbita spicata var. spicata
Eunoxis amabilis
Lactuca biennis ssp. integrifolia
Lactuca leucophaea var. integrifolia
Lactuca multifida
Lactuca spicata
Lactuca spicata var. aurea
Lactuca spicata var. integrifolia
Lactuca spicata var. multifida
Lactuca terrae-novae
Mulgedium leucophaeum var. integrifolium
Mulgedium leucophaeum var. leucophaeum
Mulgedium spicatum
Mulgedium spicatum var. integrifolium
Mulgedium spicatum var. spicatum
Sonchus biennis
Sonchus spicatus
Common Names
biennial blue lettuce
biennial lettuce
blue wood lettuce
tall blue lettuce
wild blue lettuce
wild lettuce
woodland lettuce
