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Ranunculus austro-oreganus

southern Oregon buttercup

Macoun's buttercup, renoncule de Macoun

Roots

never tuberous.

never tuberous.

Stems

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

prostrate to nearly erect, often rooting nodally, hirsute or glabrous, base not bulbous.

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.

cordate to reniform in outline, 3-foliolate, 3.7-7.5 × 4.5-9.5 cm, leaflets 3-lobed or -parted, ultimate segments elliptic or lance-elliptic, margins toothed or lobulate, apex acute to broadly acute.

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 hirsute;

sepals spreading or reflexed ca. 1 mm above base, 4-6 × 1.5-3 mm, glabrous or hirsute;

petals 5, yellow, 4-6 × 3.5-5 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, 7-11 × 7-10 mm;

achenes 2.4-3 × 2-2.4 mm, glabrous, margin forming narrow rib 0.1-0.2 mm wide;

beak persistent, lanceolate to broadly lanceolate, straight or nearly so, 1-1.2 mm.

2n

= 32, 48.

Ranunculus austro-oreganus

Ranunculus macounii

Phenology Flowering spring (May). Flowering spring–summer (May–Sep).
Habitat Grassy hillsides Meadows, depressions in woodlands, ditches, edges of streams and ponds, on wet soil or emergent from shallow water
Elevation 500 m [1600 ft] 0-2900 m [0-9500 ft]
Distribution
from FNA
OR
[WildflowerSearch map]
from FNA
AK; AZ; CA; CO; ID; MI; MN; MT; ND; NE; NM; NV; OR; SD; UT; WA; WY; AB; BC; MB; NF; NT; ON; QC; SK; YT
[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.)

Through most of its range, Ranunculus macounii has conspicuously hispid herbage. Glabrous plants are found, however, in the lower Columbia River valley (southwestern Washington and adjacent Oregon). This variant has been called R. macounii var. oreganus.

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

Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Ranunculus Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Ranunculus
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. 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. 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. macounii var. oreganus
Name authority L. D. Benson: Amer. Midl. Naturalist 52: 341. (1954) Britton: Trans. New York Acad. Sci. 12: 3. (1892)
Source FNA vol. 3. Treatment author: Alan T. Whittemore. FNA vol. 3. Treatment author: Alan T. Whittemore.
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