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Ranunculus austro-oreganus

southern Oregon buttercup

Gmelin's buttercup, Gmelin's water buttercup, lesser yellow water crowfoot, renoncule de Gmelin, small yellow water-buttercup, yellow water crowfoot

Roots

never tuberous.

Stems

erect or ascending, never rooting nodally, crisped-pilose, base not bulbous.

prostrate or sometimes floating, glabrous or hirsute, rooting nodally.

Leaves

basal leaves absent, cauline leaf blades reniform to circular, 3-parted, 0.6-6.5 × 1.1-9 cm, base cordate, segments again 1-3x-lobed to -dissected, margins entire or crenate, apex rounded to filiform.

Basal leaf blades

broadly rhombic to semicircular in outline, 3-parted, 2.8-4.3 × 3-5.5 cm, segments 3-lobed, ultimate segments lanceolate, margins entire or toothed, apex narrowly acute or acuminate.

Flowers

receptacle glabrous;

sepals reflexed 1 mm above base, 4-6 × 1.5-3 mm, densely pilose;

petals 5, abaxially red, adaxially yellow, 10-12 × 4-6 mm.

receptacle sparsely hispid;

sepals 4-5, spreading or reflexed from base, 2-5 × 2-4 mm, glabrous or sparsely pilose;

petals 4-14, 3-7 × 2-5 mm;

nectary scale variable, crescent-shaped, funnel-shaped, or flaplike;

style 0.2-0.4 mm.

Heads

of achenes hemispheric, 4-7 × 7-10 mm;

achenes 3.4-4.2 × 2.8-3.2 mm, sometimes basally pilose, margin forming narrow rib 0.1-0.2 mm wide;

beak persistent, lance-subulate, straight or somewhat curved distally, 1.6-2.6 mm.

of achenes globose or ovoid, 3-8 × 3-7 mm;

achenes 1-1.6 × 1-1.2 mm, glabrous;

beak narrowly lanceolate or filiform, 0.4-0.8 mm.

2n

= 16, 32, 64.

Ranunculus austro-oreganus

Ranunculus gmelinii

Phenology Flowering spring (May). Flowering spring–summer (May–Sep).
Habitat Grassy hillsides Shallow water or drying mud, wet meadows, swamps, marshes, ponds, shores of rivers
Elevation 500 m [1600 ft] 0-2800 m [0-9200 ft]
Distribution
from FNA
OR
[WildflowerSearch map]
from FNA
AK; CO; IA; ID; IL; ME; MI; MN; MT; ND; NM; NV; OR; UT; WA; WI; WY; AB; BC; MB; NB; NF; NS; NT; ON; PE; QC; SK; YT; Eurasia
[WildflowerSearch map]
[BONAP county map]
Discussion

Of conservation concern.

Ranunculus austro-oreganus is doubtfully distinct from R. occidentalis var. howellii. L. D. Benson (1954) described the stem as bulbous-based and similar to that of R. bulbosus, but a differentiated base is not evident in material I have seen (some of which was cited by Benson).

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

Ranunculus gmelinii has been divided into varieties on the basis of indument and flower size. These characters are variable and poorly correlated with one another, however, and these varieties scarcely seem natural.

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

Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Ranunculus Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Hecatonia
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. 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. 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. 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. 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
Synonyms R. gmelinii subsp. purshii, R. gmelinii var. hookeri, R. gmelinii var. limosus, R. gmelinii var. prolificus, R. purshii
Name authority L. D. Benson: Amer. Midl. Naturalist 52: 341. (1954) de Candolle: Syst. Nat. 1: 303. (1817)
Source FNA vol. 3. Treatment author: Alan T. Whittemore. FNA vol. 3. Treatment author: Alan T. Whittemore.
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