Ranunculus triternatus
Ranunculus aquatilis
Dalles Mountain buttercup, obscure buttercup
renoncule aquatique, water buttercup, water crowfoot, white water butter cup, white water crowfoot, white water crowsfoot, white western buttercup
cylindric, 2-3 mm thick.
prostrate or ascending, 5-20 cm, glabrous, each with 1-6 flowers.
glabrous.
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 rhombic to deltate or reniform in outline, 3-4x-dissected, 1.1-3.4 × 2-3.1 cm, segments linear, base obtuse, margins crenate, apices of segments narrowly rounded.
pedicels glabrous;
receptacle short-pubescent;
sepals 4-8 × 2-5 mm, abaxially glabrous or nearly so;
petals 5, 6-15 × 4-10 mm;
nectary scale glabrous.
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.
usually recurved.
depressed-globose, 4-6 × 5-8 mm;
achenes 1.8-2.2 × 1.2-1.8 mm, finely pubescent;
beak subulate, straight, 0.8-1.5 mm.
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.
Ranunculus triternatus
Ranunculus aquatilis
Of conservation concern.
C. L. Hitchcock et al. (1955-1969, vol. 2) considered the name Ranunculus triternatus A. Gray to be an illegitemate homonym and used the illegitimate (superfluous) name R. reconditus A. Nelson & J. F. Macbride for this species. The name Ranunculus triternatus Poiret was not validly published (not accepted by Poiret) and does not invalidate R. triternatus A. Gray.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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.)
1. Leaves of 2 types: laminate and filiform-dissected; w North America. | var. aquatilis |
1. Leaves all filiform-dissected; widespread. | var. diffusus |
- 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
