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

southern Oregon buttercup

alpine buttercup

Roots

never tuberous.

slender, 0.8-1.4 mm thick.

Stems

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

erect from large caudices, 9-25 cm, glabrous, each with 1-3 flowers.

Basal leaves

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.

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.

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.

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 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.

2

n = 16.

Ranunculus austro-oreganus

Ranunculus adoneus

Phenology Flowering spring (May).
Habitat Grassy hillsides Spring-summer (May–Sep). Alpine and subalpine meadows, usually around melting snowbanks
Elevation 500 m [1600 ft] 2500-4000 m [8200-13100 ft]
Distribution
from FNA
OR
[WildflowerSearch map]
from FNA
CO; ID; MT; NV; UT; WY
[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.)

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.)

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. 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. 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. 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. adoneus var. alpinus, R. eschscholtzii var. adoneus, R. eschscholtzii var. alpinus
Name authority L. D. Benson: Amer. Midl. Naturalist 52: 341. (1954) A. Gray: Proc. Acad. Nat. Sci. Philadelphia 15: 56. (1863)
Source FNA vol. 3. Treatment author: Alan T. Whittemore. FNA vol. 3. Treatment author: Alan T. Whittemore.
Web links