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

dwarf buttercup, pygmy buttercup

Roots

sometimes fleshy and ± tuberous.

slender, 0.1-0.6 mm thick.

Stems

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

erect or ascending from short caudices, 0.6-3.5 cm (sometimes longer in fruit), each with 1-2 flowers.

Basal leaves

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.

persistent, blades reniform to transversely elliptic or semicircular, 3-parted or -divided, 0.45-0.9 × 0.6-1.3 cm, at least lateral segments again lobed, base truncate or nearly cordate, margins entire, apex rounded to obtuse.

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.

pedicels glabrous or pubescent;

receptacle glabrous;

sepals 2-4 × 1.2-1.6 mm, abaxially sparsely hairy, hairs colorless;

petals 5, 1.2-3.5 × 1.1-2.8 mm;

nectary scale glabrous.

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.

nearly globose to cylindric, 2.5-7 × 2.5-5 mm;

achenes 1-1.2 × 0.8-1.1 mm, glabrous;

beak subulate, straight or curved, 0.3-0.7 mm.

2n

= 16.

Ranunculus orthorhynchus

Ranunculus pygmaeus

Phenology Flowering summer (Jul–Sep).
Habitat Arctic and alpine meadows and slopes, usually around persistent snow patches
Elevation 0-4000 m (0-13100 ft)
Distribution
from FNA
AK; CA; ID; MT; NV; OR; UT; WA; WY; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; CO; ID; MT; UT; WY; AB; BC; NF; NT; QC; YT; Greenland; Europe (Spitsbergen)
[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.)

Ranunculus pygmaeus var. langeana has been described as having deeply divided basal leaves and strongly elongate heads of achenes (at least 5 mm). These characteristics are not well correlated with one another, however, and the variety does not seem natural.

(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. Ranunculus > sect. Epirotes
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. lobbii, 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. 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. pygmaeus var. langeana
Name authority Hooker: Fl. Bor.-Amer. 1: 21. (1829) Wahlenberg: Fl. Lapp., 157. (1812)
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