Ranunculus aquatilis
Ranunculus eschscholtzii
renoncule aquatique, water buttercup, water crowfoot, white water butter cup, white water crowfoot, white water crowsfoot, white western buttercup
Eschscholtz's buttercup, snow buttercup, subalpine buttercup
slender, 0.4-1.6 mm thick.
glabrous.
erect or decumbent from short or long caudices, 4-27 cm, glabrous, each with 1-3 flowers.
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.
persistent, blades reniform or cordate to obovate or broadly oblong, lobed or 3-parted, 0.5-4.1 × 0.8-3.7 cm, segments again 1(-2)×-lobed, base obtuse to cordate, apices of segments rounded in outline.
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.
pedicels glabrous;
receptacle glabrous or sparsely pilose;
sepals 4-8 × 2-6 mm, abaxially glabrous or pilose;
petals 5-8, 6-16 × 4-16 mm;
nectary scale glabrous.
usually recurved.
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.
cylindric or ovoid, 5-10 × 4-7 mm;
achenes 1.4-2 × 1-1.6 mm, glabrous or sparsely pubescent;
beak lanceolate or subulate, straight (sometimes curved when immature), 0.6-1.8 mm.
Ranunculus aquatilis
Ranunculus eschscholtzii
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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 6 (5 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaves of 2 types: laminate and filiform-dissected; w North America. | var. aquatilis |
1. Leaves all filiform-dissected; widespread. | var. diffusus |
1. Ultimate segments and sinuses of basal leaves acute or acuminate. | → 2 |
1. Ultimate segments and sinuses of basal leaves rounded or obtuse (sometimes broadly rounded-acute). | → 3 |
2. Leaf blade reniform, base truncate or cordate. | var. suksdorfii |
2. Leaf blade obovate to broadly oblong, base obtuse or rounded. | var. eximius |
3. Middle segments of many basal leaves lobed and toothed or 2×-lobed. | var. trisectus |
3. Middle segments of basal leaves unlobed or 1×-lobed. | → 4 |
4. Caudices with few or no persistent leaf bases; basal leaves always 3-parted; widespread in w North America. | var. eschscholtzii |
4. Caudices densely clothed with persistent leaf bases; basal leaves sometimes parted but usually merely lobed; California and w Nevada. | var. oxynotus |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
SW CO Wildflowers
