Ranunculus aquatilis var. diffusus

Withering

Arr. Brit. Pl. ed. 3, 2: 507. 1796.

Weedy
Synonyms: Batrachium circinatum subsp. subrigidum (W. B. Drew) A. Löve & D. Löve Batrachium flaccidum (Persoon) Ruprecht Batrachium longirostris (Godron) F. W. Schultz Batrachium trichophyllum (Chaix) Bosch Batrachium trichophyllum subsp. lutulentum (Perrier & Songeon) Janchen ex V. V. Petrovsky Ranunculus aquatilis var. calvescens (W. B. Drew) L. D. Benson Ranunculus aquatilis var. capillaceus (Thuillier) de Candolle Ranunculus aquatilis var. eradicatus Laestadius Ranunculus aquatilis var. harrisii L. D. Benson Ranunculus aquatilis var. longirostris (Godron) Lawson Ranunculus aquatilis var. porteri (Britton) L. D. Benson Ranunculus aquatilis var. subrigidus (W. B. Drew) Breitung Ranunculus circinatus var. subrigidus (W. B. Drew) L. D. Benson Ranunculus confervoides Ranunculus longirostris Ranunculus subrigidus Ranunculus trichophyllus Ranunculus trichophyllus var. calvescens W. B. Drew Ranunculus trichophllus var. eradicatus (Laestadius) W. B. Drew Ranunculus trichophyllus subsp. lutulentus (Perrier & Songeon) Vierhapper
Treatment appears in FNA Volume 3.

Leaves all filiform-dissected. Achenes 1-1.8 × 0.8-1.2 mm; beak 0.2-1.2 mm. 2n = 16, 32, 48.


Phenology: Flowering spring–summer (Apr–Sep).
Habitat: Ponds, lakes, streams, ditches, edges of rivers
Elevation: 0-3200 m

Distribution

V3 44-distribution-map.gif

Greenland, Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., Idaho, Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.Mex., N.J., 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., Mexico, Eurasia, Australia

Discussion

Populations of Ranunculus aquatilis var. diffusus with long achene beaks are not known from the Old World. In North America, beak length varies continuously over the whole range given for the variety, and separation of plants with unusually long beaks as R. longirostris is not tenable. Ranunculus aquatilis var. diffusus shows geographic variation, and some regional forms have been recognized as separate varieties. Dwarf creeping arctic plants may be called R. aquatilis var. eradicatum, plants with sparsely pubescent or glabrous receptacle from eastern North America may be called R. aquatilis var. calvescens, plants with linear, noncapillary leaf segments from the northern Great Basin may be called R. aquatilis var. porteri, and very robust plants from Oregon and northernmost California may be called R. aquatilis var. harrisii. Extreme forms of these races are recognizable, but they intergrade and many specimens cannot be confidently assigned to one or another of them.

The Eurasian species Ranunculus circinatus Sibthorp has been reported from North America. These reports are based on specimens of R. aquatilis var. diffusus.

Selected References

None.

Lower Taxa

None.
48 +, 32 +  and 16 +
not prolonged +
flattened-ellipsoid +  and ellipsoid +
1-2 times as wide as thick +
0.1 cm1 mm <br />0.001 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
hispid +  and glabrous +
0.8mm;1.2mm +
Alan T. Whittemore +
Withering +
cuneate +, truncate +  and cordate +
Ranunculus sect. Batrachium +
curved +  and straight +
persistent +
filiform +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
large +  and small +
globose;cylindric +
2-50-flowered +
0 cm0 mm <br />0 m <br /> (25 cm250 mm <br />0.25 m <br />) +
Greenland +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. (Nfld.) +, N.W.T. +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Ala. +, Alaska +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Mo. +, Mont. +, Nebr. +, Nev. +, N.H. +, N.Mex. +, N.J. +, 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. +, Mexico +, Eurasia +  and Australia +
0-3200 m +
showy +  and inconspicuous +
sessile +  and aggregate +
cylindric;obovoid;cylindric;obovoid;globose;lenticular;discoid +
Ponds, lakes, streams, ditches, edges of rivers +
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 />) +
Flowering spring–summer (Apr–Sep). +
4 +  and 250 +
Arr. Brit. Pl. ed. +
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 />) +
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 circinatum subsp. subrigidum +, Batrachium flaccidum +, Batrachium longirostris +, Batrachium trichophyllum +, Batrachium trichophyllum subsp. lutulentum +, Ranunculus aquatilis var. calvescens +, Ranunculus aquatilis var. capillaceus +, Ranunculus aquatilis var. eradicatus +, Ranunculus aquatilis var. harrisii +, Ranunculus aquatilis var. longirostris +, Ranunculus aquatilis var. porteri +, Ranunculus aquatilis var. subrigidus +, Ranunculus circinatus var. subrigidus +, Ranunculus confervoides +, Ranunculus longirostris +, Ranunculus subrigidus +, Ranunculus trichophyllus +, Ranunculus trichophyllus var. calvescens +, Ranunculus trichophllus var. eradicatus +  and Ranunculus trichophyllus subsp. lutulentus +
Ranunculus aquatilis var. diffusus +
Ranunculus aquatilis +
variety +
perennial +  and annual +
herbaceous +  and woody +