Ranunculus adoneus
Ranunculus californicus
alpine buttercup
California buttercup, common buttercup
slender, 0.8-1.4 mm thick.
never tuberous.
erect from large caudices, 9-25 cm, glabrous, each with 1-3 flowers.
erect to prostrate, never rooting nodally, hirsute, strigose, or glabrous, base not bulbous.
persistent, blades circular to reniform in outline, 2-3x-dissected into linear segments, 0.9-2.5 × 1.1-2.8 cm, base obtuse, margins entire, apices of segments narrowly rounded to acute.
blades broadly ovate or cordate in outline, 3-lobed or -parted to 3-foliolate, 1.8-5.8 × 2.3-7.6 cm, leaflets or segments undivided or 1-2x-lobed or -parted, ultimate segments linear to orbiculate, margins toothed, crenate, or entire, apex acute to rounded.
pedicels glabrous;
receptacle glabrous;
sepals 4-11 × 3-7 mm, abaxially sparsely pilose, hairs colorless;
petals 5-10, 8-15 × 8-19 mm;
nectary scale glabrous.
receptacle glabrous or rarely hispid;
sepals reflexed 2-3 mm above base, 4-8 × 2-4 mm, pilose;
petals 9-17, yellow, (6-)7-14 × 2-6 mm.
ovoid, 6-12 × 5-9 mm;
achenes 1.8-2.4 × 1-1.4 mm, glabrous or nearly so;
beak subulate, straight, 1.2-1.7 mm.
globose or hemispheric, 3-7 × 4-9 mm;
achenes 1.8-3.2 × 1.4-3.2 mm, glabrous, rarely hispid, margin forming narrow rib 0.1-0.2 mm wide;
beak persistent, lanceolate, curved, 0.2-0.8 mm.
n = 16.
Ranunculus adoneus
Ranunculus californicus
Most collections of Ranunculus adoneus from Colorado, including the type specimen, tend to be small, with narrow leaf segments (only 0.5-1 mm wide) and large flowers. The more widespread form, with leaf segments 1-2 mm wide and more variable flowers, has been called R. adoneus var. alpinus. The leaf and flower characteristics are very poorly correlated, however, and specimens referable to var. alpinus vary greatly in stature and flower size, so the two forms scarcely merit formal recognition.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (2 in the flora).
In addition to the range given, localized populations of Ranunculus californicus have been reported recently from a few islands in the vicinity of Victoria (British Columbia and Washington) (M. F. Denton 1978; T. C. Brayshaw 1989). Those populations are small and introgress freely with R. occidentalis wherever they come together. Denton referred her specimens to R. californicus var. cuneatus; Brayshaw reported both varieties from the same small populations, but his data are consistent with populations of R. californicus var. cuneatus that are introgressing extensively with R. occidentalis. Although both Denton and Brayshaw treat R. californicus as a native species in that region, several reasons support the belief that it is introduced there. No reports of R. californicus in the area occur prior to 1978, although the area is quite well collected (especially Victoria, B. C. and the San Juan Islands, Washington); a long history of extensive marine trade between Victoria and San Francisco has resulted in the introduction of a number of other California species to the area; and for scattered small populations of R. californicus to have persisted for long periods in the face of free introgression from R. occidentalis seems unlikely. Given the small population size and the introgression from R. occidentalis, it is questionable whether R. californicus can persist in the area.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Stems erect to decumbent, hirsute or glabrous; ultimate segments of basal leaf blades acute to rounded-acute at apex. | var. californicus |
1. Stems prostrate, strigose; ultimate segments of basal leaf blades rounded to obtuse at apex. | var. cuneatus |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
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USDA Plants Database- LBJ Wildflower Center
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