Lactuca biennis

(Moench) Fernald
Rhodora 42: 300. 1940.
IllustratedEndemic
Basionym: Sonchus biennis Moench Methodus, 545. 1794
Treatment appears in FNA Volume 19. Treatment on page 261. Mentioned on page 260.

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.


Phenology: Flowering Jul–Oct.
Habitat: Swamps, stream banks, woods
Elevation: 900–1500 m

Distribution

V19-348-distribution-map.gif

St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que., Sask., Yukon, Alaska, Calif., Colo., Conn., Del., D.C., Idaho, Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mont., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Oreg., Pa., R.I., S.Dak., Tenn., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.

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.

Selected References

None.

Lower Taxa

None.

... more about "Lactuca biennis"
John L. Strother +
(Moench) Fernald +
Sonchus biennis +
St. Pierre and Miquelon +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Alaska +, Calif. +, Colo. +, Conn. +, Del. +, D.C. +, Idaho +, Ill. +, Ind. +, Iowa +, Ky. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Mont. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, N.Dak. +, Ohio +, Oreg. +, Pa. +, R.I. +, S.Dak. +, Tenn. +, Utah +, Vt. +, Va. +, Wash. +, W.Va. +, Wis. +  and Wyo. +
900–1500 m +
Swamps, stream banks, woods +
Flowering Jul–Oct. +
Illustrated +  and Endemic +
Undefined tribe Lactuceae +
Lactuca biennis +
species +