Lactuca sativa

Linnaeus

Sp. Pl. 2: 795. 1753.

Introduced
Treatment appears in FNA Volume 19. Treatment on page 263. Mentioned on page 260.

Annuals or biennials, (15–) 30–70 (–100+) cm. Leaves on proximal 1/2–3/4 of each stem; blades of undivided cauline leaves ovate to orbiculate, margins entire or denticulate, seldom prickly, midribs rarely prickly-setose. Heads usually in corymbiform, sometimes in paniculiform, arrays. Involucres 8–13+ mm. Phyllaries usually erect in fruit. Florets 7–15 (–30+); corollas yellow (sometimes streaked with violet), usually deliquescent. Cypselae: bodies pale grayish to whitish or tan, ± flattened, obovate, 3–4 mm, beaks ± filiform, 3–5 mm, faces 5–9-nerved; pappi white, 3.5–4+ mm. 2n = 18.


Phenology: Flowering mostly Jul–Sep.
Habitat: Disturbed sites, abandoned plantings
Elevation: 10–1000 m

Distribution

V19-357-distribution-map.gif

Introduced; Ont., Ala., Calif., Conn., Del., D.C., Idaho, Ill., Ind., Maine, Mass., Mich., Mo., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., Vt., Wash., W.Va., Eurasia, also in Mexico, or ephemeral nearly worldwide

Discussion

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Lactuca sativa"
obtuse;acute +
scarious +
ovate +  and lanceolate +
corymbiform +  and paniculiform +
indeterminate +  and determinate +
John L. Strother +
Linnaeus +
decurrent +
filiform +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
compound +  and simple +
lanceolate;oblanceolate linear or filiform +
pale grayish +  and whitish or tan +
tuberculate +, rugose +, muricate +  and smooth +
obovate;flattened +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
deltate;lanceolate +
filiform +
simple +, barbellulate +  and nearly smooth +
zygomorphic +, actinomorphic +  and (3-)5-merous +
fuscous +  and white +
subtending +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
purplish +  and blackish +
tapered +, beaked +, flattened +, obcompressed +, compressed +, prismatic +, fusiform +, ellipsoid +, columnar +  and clavate +
Ont. +, Ala. +, Calif. +, Conn. +, Del. +, D.C. +, Idaho +, Ill. +, Ind. +, Maine +, Mass. +, Mich. +, Mo. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, N.Dak. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, Vt. +, Wash. +, W.Va. +, Eurasia +, also in Mexico +  and or ephemeral nearly worldwide +
10–1000 m +
rugulose +
winged +  and beaked +
dispersed +
Disturbed sites, abandoned plantings +
in corymbiform to paniculiform arrays +  and singly +
indeterminate +
each +  and sessile +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
campanulate;cylindric +
0.8 cm8 mm <br />0.008 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
petiolate +  and sessile +
cauline +  and basal +
denticulate +  and entire +
prickly-setose +
2-carpellate +
persistent +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Flowering mostly Jul–Sep. +
connate +  and distinct +
5 +  and 13 +
flat;convex +
1 +  and 9 +
exalbuminous +
Introduced +
hairy +  and glabrous +
appendaged +  and truncate +
papillate +
Undefined tribe Lactuceae +
Lactuca sativa +
species +
70 cm700 mm <br />0.7 m <br /> (100 cm1,000 mm <br />1 m <br />) +
biennial +  and annual +
30 cm300 mm <br />0.3 m <br /> (70 cm700 mm <br />0.7 m <br />) +
shrub +  and subshrub +