Taraxacum officinale

F. H. Wiggers

Prim. Fl. Holsat., 56. 1780.

Common names: Common dandelion pissenlit officinal
Introduced
Basionym: Leontodon taraxacum Linnaeus Sp. Pl. 2: 798. 1753
Synonyms: Taraxacum officinale var. palustre Blytt Taraxacum sylvanicum
Treatment appears in FNA Volume 19. Treatment on page 244. Mentioned on page 7, 239, 240, 241, 242, 243, 245, 246.

Plants (1–) 5–40 (–60) cm; taproots seldom branched. Stems 1–10+, erect or ascending, sometimes ± purplish (usually equaling or surpassing leaves), glabrous or sparsely villous, slightly more so distally. Leaves 20+, horizontal to erect; petioles ± narrowly winged; blades oblanceolate, oblong, or obovate (often runcinate), (4–) 5–45 × (0.7–) 1–10 cm, bases attenuate to narrowly cuneate, margins usually shallowly to deeply lobed to lacerate or toothed, lobes retrorse, broadly to narrowly triangular to nearly lanceolate, acute to long-acuminate, terminals ± as large as distal laterals, ultimate margins toothed or entire (secondary lobules irregular, perpendicular to retrorse), teeth minute to pronounced apices acute to acuminate or obtuse, faces glabrous or sparsely villous (commonly on midveins). Calyculi of 12–18, reflexed, sometimes ± glaucous, lanceolate bractlets in 2 series, 6–12 × 2.8–3.5 mm, margins very narrowly white-scarious, sometimes villous-ciliate distally, apices acuminate, hornless. Involucres green to dark green or brownish green, tips dark gray or purplish, campanulate, 14–25 mm. Phyllaries 13–18 in 2 series, lanceolate, 2–2.8 mm wide, margins scarious (proximal 2/3) to narrowly scarious, apices acuminate, erose-scarious, usually hornless (seldom appendaged), callous. Florets 40–100+; corollas yellow (orange-yellow), 15–22 × 1.7–2 mm (outer). Cypselae olivaceous or olive-brown, or straw-colored to grayish, bodies oblanceoloid, (2–) 2.5–2.8 (–4) mm, cones shortly terete, 0.5–0.9 mm, beaks slender, 7–9 mm, ribs 4–12, sharp, faces proximally smooth to ± tuberculate, muricate in distal 1/3; pappi white to sordid, 5–6 (–8) mm. 2n = 24, 40, [16, 32].


Phenology: Flowering nearly year-round (fall–spring, south; spring or summer, north).
Habitat: Often damp low places, lawns, roadsides, waste grounds, disturbed banks and shores
Elevation: 0–2000+ m

Distribution

V19-318-distribution-map.gif

Introduced; Greenland, St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Europe, also in Mexico, nearly worldwide

Discussion

Taraxacum officinale is the most widespread dandelion in temperate North America, though its abundance decreases in the arid south. It is a familiar weed of lawns and roadsides. It is also the species most commonly used for medicinal and culinary purposes (e.g., E. Small and P. M. Catling 1999).

Phenotypic and genotypic variation of this species have been studied in North America (L. M. King 1993; King and B. A. Schaal 1990; J. C. Lyman and N. C. Ellstrand 1998; O. T. Solbrig 1971; R. J. Taylor 1987), but results of those studies did not lead to the recognition of microspecies.

Specimens of Taraxacum officinale with deeply lobed leaves are sometimes difficult to distinguish from those of T. erythrospermum when fruits are missing (see also R. J. Taylor 1987). Usually, however, early leaves of the former are much less deeply lobed than those of the latter, which are more consistently lacerate throughout development, though broadly winged initially. The two taxa are easily distinguished in fruit, the red cypselae of T. erythrospermum standing out from the dull olive ones of T. officinale.

In northeastern North America, Taraxacum officinale and T. lapponicum often are confused, which has led to reports of the common dandelion farther north than I have been able to verify (it has yet to be collected from the Nunavik region of Quebec, for instance). The characters in the key above help separate the two taxa.

The typification by A. J. Richards (1985) would leave the common dandelion of both Europe and North America without a valid name (J. Kirschner and J. Štepánek 1987). For the time being, with the nomenclatural situation still not resolved, I am following traditional usage of the name Taraxacum officinale.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Taraxacum officinale"
32] +, [16 +, 40 +  and 24 +
pronounced +
hornless;acuminate;hornless;acuminate;acute;acuminate or obtuse +
callous +  and erose-scarious +
ovate +  and lanceolate +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
Luc Brouillet +
F. H. Wiggers +
attenuate +  and narrowly cuneate +
Leontodon taraxacum +
slender +
0.7 cm7 mm <br />0.007 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
compound +  and simple +
4 cm40 mm <br />0.04 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
5 cm50 mm <br />0.05 m <br /> (45 cm450 mm <br />0.45 m <br />) +
obovate;oblong;obovate;oblong;oblanceolate +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
tuberculate +, rugose +, muricate +  and smooth +
oblanceoloid +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
lanceolate +
filiform +
white +  and cream-colored or yellowish +
0.6 cm6 mm <br />0.006 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Common dandelion +  and pissenlit officinal +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
zygomorphic +, actinomorphic +  and (3-)5-merous +
1.5 cm15 mm <br />0.015 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
olive-brown or straw-colored +  and grayish +
tapered +, beaked +, flattened +, obcompressed +, compressed +, prismatic +, fusiform +, ellipsoid +, columnar +  and clavate +
Greenland +, St. Pierre and Miquelon +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. +, N.W.T. +, N.S. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Ala. +, Alaska +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Mont. +, Nebr. +, Nev. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, N.Dak. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Vt. +, Va. +, Wash. +, W.Va. +, Wis. +, Wyo. +, Europe +, also in Mexico +  and nearly worldwide +
0–2000+ m +
villous +  and glabrous +
muricate +, proximally smooth +  and more or less tuberculate +
winged +  and beaked +
dispersed +
Often damp low places, lawns, roadsides, waste grounds, disturbed banks and shores +
indeterminate +
each +  and sessile +
green +  and dark green or brownish green +
0.8 cm8 mm <br />0.008 m <br /> (4 cm40 mm <br />0.04 m <br />) +
campanulate;cylindro-campanulate or urceolate +
sessile +  and petiolate +
horizontal +  and erect +
triangular +  and nearly lanceolate acute +
lobed +  and lacerate or toothed +
scarious +  and narrowly scarious +
2-carpellate +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
white +  and sordid +
persistent +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Flowering nearly year-round (fall–spring, south +  and spring or summer, north). +
closing +  and later +
distinct +  and coherent +
13 +  and 18 +
subequal +  and unequal +
0.2 cm2 mm <br />0.002 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
Prim. Fl. Holsat., +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
4 +  and 12 +
exalbuminous +
Introduced +
1 (?) +  and 10 (?) +
ascending +  and erect +
villous +  and glabrous +
1 +  and 10 +
scapiform +
appendaged +  and truncate +
papillate +
Taraxacum officinale var. palustre +  and Taraxacum sylvanicum +
Taraxacum officinale +
Taraxacum +
species +
purplish +  and dark gray +
campanulate +
1.4 cm14 mm <br />0.014 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
entire +  and toothed +
with branched caudices +  and taprooted +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
30 cm300 mm <br />0.3 m <br /> (400 cm4,000 mm <br />4 m <br />) +
40 cm400 mm <br />0.4 m <br /> (60 cm600 mm <br />0.6 m <br />) +