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Ranunculus austro-oreganus

southern Oregon buttercup

ficaire, fig buttercup, lesser celandine, pilewort, renoncule ficaire

Roots

never tuberous.

Stems

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

erect to decumbent, not rooting nodally, glabrous, not bulbous-based, spheric or ellipsoid bulbils sometimes formed in leaf axils.

Basal leaves

simple and undivided, blades cordate to deltate or semicircular, 1.8-3.7 × 2-4 cm, base cordate, margins entire or crenate, apex rounded or obtuse.

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 glabrous;

sepals spreading, saccate at extreme base, 4-9 × 3-6 mm, glabrous;

petals yellow, 10-15 × 3-7 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 hemispheric, 4-5 × 6-8 mm;

achenes 2.6-2.8 × 1.8-2 mm, pubescent;

beak absent.

Tuberous

roots present.

Ranunculus austro-oreganus

Ranunculus ficaria

Phenology Flowering spring (May). Flowering spring (Apr–May).
Habitat Grassy hillsides Shaded stream banks and moist disturbed areas
Elevation 500 m [1600 ft] 0-300 m [0-1000 ft]
Distribution
from FNA
OR
[WildflowerSearch map]
from FNA
CT; DC; IL; KY; MA; MD; MI; MO; NJ; NY; OH; OR; PA; RI; TN; VA; WA; WV; BC; NF; ON; QC; native to Europe [Introduced in North America]
[WildflowerSearch 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.)

In North America, Ranunculus ficaria seems to be expanding its range rapidly in areas with cool mesic climates.

The species is extremely variable (especially in leaf size and stem posture), and many attempts have been made to divide it into varieties or subspecies (see P. D. Sell 1994). The different forms, however, intergrade extensively and the varieties are often impossible to distinguish.

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

Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Ranunculus Ranunculaceae > Ranunculus > subg. Ficaria
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. 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. ficaria subsp. bulbifer, R. ficaria subsp. calthifolius, R. ficaria var. bulbifera
Name authority L. D. Benson: Amer. Midl. Naturalist 52: 341. (1954) Linnaeus: Sp. Pl. 1: 550. (1753)
Source FNA vol. 3. Treatment author: Alan T. Whittemore. FNA vol. 3. Treatment author: Alan T. Whittemore.
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