Ranunculus aquatilis

Linnaeus

Sp. Pl. 1: 556. 1753.

Common names: White water crowsfoot renoncule aquatique
Illustrated
Synonyms: Batrachium aquatile (Linnaeus) Dumortier
Treatment appears in FNA Volume 3.

Stems glabrous. Leaves laminate and filiform-dissected; laminate leaf-blades reniform, 3-parted, 0.4-1.1 × 0.7-2.3 cm, segments obovate or fan-shaped, shallowly cleft, margins crenate; filiform-dissected leaves with stipules gradually tapering upward, connate for their whole length. Flowers: receptacle hispid, rarely glabrous; sepals spreading or reflexed, 2-4 × 1-2 mm, glabrous; petals 5, 4-7 × 1-5 mm; style 0.1-0.8 mm. Fruiting pedicels usually recurved. Heads of achenes hemispheric to ovoid, 2-4 × 2-5 mm; achenes 1-2 × 0.8-1.4 mm, glabrous or hispid; beak persistent, filiform, 0.1-1.2 mm.

Distribution

Alta., B.C., Man., N.B., N.S., N.W.T., Nfld. and Labr. (Nfld.), Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., Idaho, Ill., Ind., Iowa, Kans., Ky., Maine, Mass., Md., Mich., Minn., Mo., Mont., N.C., N.Dak., N.H., N.J., N.Mex., N.Y., Nebr., Nev., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Va., Vt., W.Va., Wash., Wis., Wyo., Eurasia

Discussion

Varieties 2 (2 in the flora).

Ranunculus aquatilis is very variable. In the past it has often been treated as three or four species and many varieties. These segregate taxa have been based on the size, petiolation and rigidity of the leaves (now known to be primarily under environmental control), petal size and curvature of the fruiting pedicel (both sometimes variable along single stem), and number of achenes per head and length of achene beak (which vary continuously and are not correlated with one another). Unless reliable characters can be found, only two of the taxa recognized in older floras can be maintained.

Selected References

None.

Key

1 Leaves of 2 types: laminate and filiform-dissected; w North America. Ranunculus aquatilis var. aquatilis
1 Leaves all filiform-dissected; widespread. Ranunculus aquatilis var. diffusus
... more about "Ranunculus aquatilis"
not prolonged +
flattened-ellipsoid +  and ellipsoid +
1-2 times as wide as thick +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
hispid +  and glabrous +
0.8mm;1.4mm +
Alan T. Whittemore +
Linnaeus +
cuneate +, truncate +  and cordate +
Ranunculus sect. Batrachium +
curved +  and straight +
persistent +
filiform +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
large +  and small +
globose;cylindric +
White water crowsfoot +  and renoncule aquatique +
2-50-flowered +
0 cm0 mm <br />0 m <br /> (25 cm250 mm <br />0.25 m <br />) +
Alta. +, B.C. +, Man. +, N.B. +, N.S. +, N.W.T. +, Nfld. and Labr. (Nfld.) +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Ala. +, Alaska +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, Maine +, Mass. +, Md. +, Mich. +, Minn. +, Mo. +, Mont. +, N.C. +, N.Dak. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, Nebr. +, Nev. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Va. +, Vt. +, W.Va. +, Wash. +, Wis. +, Wyo. +  and Eurasia +
showy +  and inconspicuous +
sessile +  and aggregate +
cylindric;obovoid;cylindric;obovoid;globose;lenticular;discoid +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
hemispheric;ovoid +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (2.3 cm23 mm <br />0.023 m <br />) +
whorled +, opposite +  and alternate +
connate +
filiform-dissected +
palmate +  and pinnate +
distinct +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
conspicuous +
reduced +
0.1 cm1 mm <br />0.001 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
4 +  and 250 +
glabrous +  and hispid +
not arillate +  and stalked +
entire to shallowly +
white;yellow;white;yellow;purple;sometimes;green +
deciduous +
distinct +
reflexed +  and spreading +
oblong +  and elliptic ovate or lanceolate +
0.1 cm1 mm <br />0.001 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Illustrated +
not bulbous-based +
floating +  and creeping +
persistent +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
Batrachium aquatile +
Ranunculus aquatilis +
Ranunculus subg. Batrachium +
species +
perennial +  and annual +
herbaceous +  and woody +