The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Bloomer's buttercup, straight-beak buttercup, swamp buttercup

Lobb's aquatic buttercup, Lobb's buttercup, Lobb's water-buttercup

Roots

sometimes fleshy and ± tuberous.

Stems

nearly erect or decumbent, never rooting nodally, hispid, strigose, or glabrous, base not bulbous.

glabrous.

Leaves

laminate and filiform-dissected; laminate leaf blades reniform in outline, deeply 3-parted, 0.5-0.8 × 0.9-1.5 cm, segments elliptic or obovate, margins sometimes notched;

filiform-dissected leaves sometimes few and inconspicuous, stipules gradually tapering upward, connate for whole length, mostly petiolate.

Basal leaf

blades narrowly ovate to oblong or semicircular in outline, simple to 3-5-lobed or -foliolate, 2.8-12.5 × 2.5-14 cm, leaflets or segments undivided or 1-2x-lobed or -parted, ultimate segments circular to linear, margins dentate, crenate, or entire, apex rounded to narrowly acute.

Flowers

receptacle hispid;

sepals reflexed 1-2 mm above base, 5-11 × 2-4 mm, hispid, hirsute, or glabrous;

petals 5-6, abaxially yellow or red, adaxially yellow, 8-18 × 4-11 mm.

receptacle glabrous;

sepals spreading, 2-3 × 1-1.5 mm, glabrous;

petals 5, 4-6 × 2-5 mm;

style 1-1.5 mm.

Fruiting pedicels

recurved.

Heads of achenes

hemispheric to ovoid, 5-13 × 6-10 mm;

achenes 2.8-4.5 × 1.8-3.2 mm, glabrous, margin forming narrow rib 0.1-0.2 mm wide;

beak persistent, narrowly lanceolate to subulate, straight, 1.8-3.8(-4.8) mm.

hemispheric, 3 × 4-5 mm;

achenes 2-2.4 × 1.4-1.8 mm, glabrous;

beak deciduous, sometimes leaving stub to 0.2 mm.

Ranunculus orthorhynchus

Ranunculus lobbii

Phenology Flowering late winter–spring (Mar–May).
Habitat Shallow ponds and vernal pools
Elevation 0-300 m (0-1000 ft)
Distribution
from FNA
AK; CA; ID; MT; NV; OR; UT; WA; WY; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; OR; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 3

The first two varieties (Ranunculus orthorhynchus var. orthorhynchus and R. orthorhynchus var. platyphyllus) are rather weak, intergrading extensively in California and Oregon. By contrast, R. orthorhynchus var. bloomeri often grows with the others with little or no intergradation (although intermediate populations are found in some areas), and it has been treated as a distinct species, R. bloomeri, by many taxonomists.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Basal leaves simple or 3-foliolate, if compound then leaflets undivided, margins crenate; petals retuse.
var. bloomeri
1. Basal leaves 3–5-foliolate, leaflets lobed or parted, margins entire or dentate; petals truncate or rounded.
→ 2
2. Heads of achenes hemispheric or sometimes globose, 5–7 mm; petals often abaxially red.
var. orthorhynchus
2. Heads of achenes globose or ovoid, 8–13 mm; petals yellow.
var. platyphyllus
Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Ranunculus Ranunculaceae > Ranunculus > subg. Batrachium
Sibling taxa
R. abortivus, R. acriformis, R. acris, R. adoneus, R. alismifolius, R. allegheniensis, R. allenii, R. ambigens, R. andersonii, R. aquatilis, R. arizonicus, R. arvensis, R. auricomus, R. austro-oreganus, R. bonariensis, R. bulbosus, R. californicus, R. canus, R. cardiophyllus, R. cooleyae, R. cymbalaria, R. eschscholtzii, R. fascicularis, R. fasciculatus, R. ficaria, R. flabellaris, R. flammula, R. gelidus, R. glaberrimus, R. glacialis, R. gmelinii, R. gormanii, R. harveyi, R. hebecarpus, R. hederaceus, R. hispidus, R. hydrocharoides, R. hyperboreus, R. hystriculus, R. inamoenus, R. jovis, R. kamtschaticus, R. lapponicus, R. laxicaulis, R. lobbii, R. macauleyi, R. macounii, R. macranthus, R. marginatus, R. micranthus, R. muricatus, R. nivalis, R. occidentalis, R. oresterus, R. pacificus, R. pallasii, R. parviflorus, R. pedatifidus, R. pensylvanicus, R. platensis, R. populago, R. pusillus, R. pygmaeus, R. ranunculinus, R. recurvatus, R. repens, R. rhomboideus, R. sabinei, R. sardous, R. sceleratus, R. sulphureus, R. testiculatus, R. trilobus, R. triternatus, R. turneri, R. uncinatus
R. abortivus, R. acriformis, R. acris, R. adoneus, R. alismifolius, R. allegheniensis, R. allenii, R. ambigens, R. andersonii, R. aquatilis, R. arizonicus, R. arvensis, R. auricomus, R. austro-oreganus, R. bonariensis, R. bulbosus, R. californicus, R. canus, R. cardiophyllus, R. cooleyae, R. cymbalaria, R. eschscholtzii, R. fascicularis, R. fasciculatus, R. ficaria, R. flabellaris, R. flammula, R. gelidus, R. glaberrimus, R. glacialis, R. gmelinii, R. gormanii, R. harveyi, R. hebecarpus, R. hederaceus, R. hispidus, R. hydrocharoides, R. hyperboreus, R. hystriculus, R. inamoenus, R. jovis, R. kamtschaticus, R. lapponicus, R. laxicaulis, R. macauleyi, R. macounii, R. macranthus, R. marginatus, R. micranthus, R. muricatus, R. nivalis, R. occidentalis, R. oresterus, R. orthorhynchus, R. pacificus, R. pallasii, R. parviflorus, R. pedatifidus, R. pensylvanicus, R. platensis, R. populago, R. pusillus, R. pygmaeus, R. ranunculinus, R. recurvatus, R. repens, R. rhomboideus, R. sabinei, R. sardous, R. sceleratus, R. sulphureus, R. testiculatus, R. trilobus, R. triternatus, R. turneri, R. uncinatus
Subordinate taxa
R. orthorhynchus var. bloomeri, R. orthorhynchus var. orthorhynchus, R. orthorhynchus var. platyphyllus
Synonyms R. hydrocharis
Name authority Hooker: Fl. Bor.-Amer. 1: 21. (1829) (Hiern) A. Gray: Proc. Amer. Acad. Arts 21: 364. (1886)
Web links