Ranunculus aquatilis
Ranunculus uncinatus
renoncule aquatique, water buttercup, water crowfoot, white water butter cup, white water crowfoot, white water crowsfoot, white western buttercup
hook fruit buttercup, little buttercup, woodland buttercup
never tuberous.
glabrous.
erect, never rooting nodally, hispid or glabrous, base not bulbous.
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.
blades cordate to reniform in outline, 3-parted or sometimes 3-foliolate, 1.8-5.6 × 2.8-8.3 cm, segments again lobed, ultimate segments elliptic to lanceolate, margins toothed or crenate-toothed, apex acute to rounded-obtuse.
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.
receptacle glabrous;
sepals reflexed or sometimes spreading, 2-3.5 × 1-2 mm, pubescent;
petals 5, yellow, 2-4(-6) × 1-2(-3) mm.
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.
globose or hemispheric, 4-7 × 4-7 mm;
achenes 2-2.8 × 1.6-2 mm, glabrous or sparsely hispid, margin forming narrow rib 0.1-0.2 mm wide;
beak persistent, lanceolate, curved, hooked, 1.2-2.5 mm.
= 28.
Ranunculus aquatilis
Ranunculus uncinatus
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.)
Plants with hispid stems and achenes are often separated as Ranunculus uncinatus var. parviflorus; these two characters are poorly correlated, however, and sometimes vary between plants in a single collection. Ranunculus uncinatus was reported from northeastern Alberta and adjacent Northwest Territories by H. J. Scoggan (1978-1979, part 3). The specimens have hairy receptacles and straight, broad achene beaks; they apparently represent small individuals of R. macounii.
Some Native Americans used Ranunculus uncinatus as an antrirheumatic, a diaphoretic, a disinfectant, and an orthopedic aid, as well as in herbal steam baths intended to soothe sore muscles and rheumatism (D. E. Moerman 1986).
(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
SW CO Wildflowers
