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Lactuca biennis (Moench) Fernald

Tall blue lettuce (en)

Species

Angiosperms > Asterales > Asteraceae > Lactuca

Characteristics

Robust, leafy-stemmed annual or biennial, 6-20 dm, glabrous, or the lvs hairy on the main veins beneath; lvs pinnatifid or occasionally merely toothed, 10-40 × 4-20 cm, sometimes sagittate at the base; heads numerous in an elongate, rather narrow, paniculiform infl, often crowded, with 15-34(-55) bluish to white or occasionally yellow fls; invol 10-14 mm in fr; achenes 4-5.5 mm, thin-edged, prominently several-nerved on each face, tapering to a beakless or shortly stout-beaked tip; pappus light brown; 2n=34. Moist places; Nf. to B.C., s. to N.C. (chiefly in the mts.), Ill., Colo., and Calif. (L. spicata, misapplied) An apparent hybrid with no. 3 [Lactuca canadensis L.] has been called L. ×morssii Robinson.
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Annuals or biennials, (15–)75–200(–300+) cm. Leaves on proximal 2/3–3/4 of each stem; blades of undivided cauline leaves ovate to lanceolate, margins entire or denticulate, midribs sometimes sparsely piloso-setose. Heads in paniculiform arrays. Involucres 7–12+ mm. Phyllaries usually reflexed in fruit. Florets (15–)20–30(–50+); corollas bluish or whitish, sometimes yellowish, seldom deliquescent. Cypselae: bodies brown (often mottled), ± compressed-ellipsoid, 4–5+ mm, beaks ± stout, 0.1–0.5+ mm, faces (4–)5–6-nerved; pappi ± fuscous, 4–6+ mm. 2n = 34.
A tall leafy herb. It has a taproot. There are leaves scattered along the stem. There are several flower heads. They are bluish.
Life form annual
Growth form herb
Growth support free-standing
Foliage retention -
Sexuality hermaphrodite
Pollination -
Spread -
Mature width (meter) -
Mature height (meter) 0.88 - 1.5
Root system tap-root
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway -

Environment

Swamps, stream banks, woods; at elevations from 900-1,500 metres.
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It is a temperate plant.
Light 4-8
Soil humidity 5-8
Soil texture 1-6
Soil acidity 3-7
Soil nutriment -
Hardiness (USDA) 4-9

Usage

Uses medicinal
Edible leaves
Therapeutic use Analgesic (root), Antidiarrheal (root), Antiemetic (root), Antihemorrhagic (root), Heart Medicine (root), Gynecological Aid (unspecified), Unspecified (unspecified)
Human toxicity -
Animal toxicity -

Cultivation

Can be grown by seedlings.
Mode seedlings
Germination duration (days) -
Germination temperacture (C°) -
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Leaf

Lactuca biennis leaf picture by Skylar Austin (cc-by-sa)
Lactuca biennis leaf picture by Marilyse Goulet (cc-by-sa)
Lactuca biennis leaf picture by Marilyse Goulet (cc-by-sa)

Flower

Lactuca biennis flower picture by Marilyse Goulet (cc-by-sa)
Lactuca biennis flower picture by Marilyse Goulet (cc-by-sa)

Distribution

Lactuca biennis world distribution map, present in Canada, France, Saint Pierre and Miquelon, and United States of America

Identifiers

LSID urn:lsid:ipni.org:names:134512-2
WFO ID wfo-0000033444
COL ID 3RSZV
BDTFX ID 65227
INPN ID 761994
Wikipedia (EN) Link
Wikipedia (FR)

Synonyms

Mulgedium spicatum Cicerbita spicata Agathyrsus floridanus Sonchus biennis Lactuca biennis f. biennis Sonchus spicatus Lactuca spicata f. spicata Cicerbita spicata var. spicata Mulgedium leucophaeum var. leucophaeum Lactuca spicata var. spicata Mulgedium spicatum var. spicatum Mulgedium spicatum var. integrifolium Lactuca biennis
WorldFloraDB 2024