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Canada lettuce, Canada wild lettuce, Canadian wild lettuce, Florida blue lettuce, tall lettuce, wild lettuce

biennial wild lettuce, tall blue lettuce, wild blue lettuce

Habit Biennials, (15–)40–200(–450+) cm. Annuals or biennials, (15–)75–200(–300+) cm.
Leaves

on proximal 1/2–3/4 of each stem;

blades of undivided cauline leaves oblong, obovate, or lanceolate to spatulate or lance-linear, margins entire or denticulate, midribs sometimes sparsely pilose.

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.

Involucres

10–12+ mm.

7–12+ mm.

Florets

15–20+;

corollas bluish or yellowish, usually deliquescent.

(15–)20–30(–50+);

corollas bluish or whitish, sometimes yellowish, seldom deliquescent.

Phyllaries

usually reflexed in fruit.

usually reflexed in fruit.

Heads

in ± corymbiform to paniculiform arrays.

in paniculiform arrays.

Cypselae

bodies brown (often mottled), ± flattened, elliptic, 5–6 mm, beaks ± filiform, 1–3 mm, faces 1(–3)-nerved;

pappi white, 5–6 mm.

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.

= 34.

Lactuca canadensis

Lactuca biennis

Phenology Flowering Jun–Oct. Flowering Jul–Oct.
Habitat Roadsides, swamps, salt marshes, thickets Swamps, stream banks, woods
Elevation 0–2200 m (0–7200 ft) 900–1500 m (3000–4900 ft)
Distribution
from FNA
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; BC; MB; NB; NS; ON; PE; QC; YT; Mexico; Central America; Eurasia
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; CA; CO; CT; DC; DE; IA; ID; IL; IN; KY; MA; MD; ME; MI; MN; MT; NC; ND; NH; NJ; NM; NY; OH; OR; PA; RI; SD; TN; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; ON; PE; QC; SK; YT; SPM
[WildflowerSearch map]
[BONAP county map]
Discussion

The type of Lactuca terrae-novae Fernald is probably conspecific with that of L. biennis. The type of L. biennis may be conspecific with that of L. floridana.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 19, p. 261. FNA vol. 19, p. 261.
Parent taxa Asteraceae > tribe Cichorieae > Lactuca Asteraceae > tribe Cichorieae > Lactuca
Sibling taxa
L. biennis, L. floridana, L. graminifolia, L. hirsuta, L. ludoviciana, L. saligna, L. sativa, L. serriola, L. virosa
L. canadensis, L. floridana, L. graminifolia, L. hirsuta, L. ludoviciana, L. saligna, L. sativa, L. serriola, L. virosa
Synonyms L. canadensis var. latifolia, L. canadensis var. longifolia, L. canadensis var. obovata, L. sagittifolia Sonchus biennis
Name authority Linnaeus: Sp. Pl. 2: 796. (1753) (Moench) Fernald: Rhodora 42: 300. (1940)
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