Ranunculus austro-oreganus |
Ranunculus pusillus |
|
|---|---|---|
|
southern Oregon buttercup |
low buttercup, low spearwort, weak buttercup |
|
| Roots | never tuberous. |
not thickened basally, glabrous. |
| Stems | erect or ascending, never rooting nodally, crisped-pilose, base not bulbous. |
erect or ascending, rooting at most proximal nodes, glabrous. |
| 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. |
|
| Proximal cauline leaf blades | ovate or lanceolate, 1.2-4.2 × 0.5-1.2 cm, base acute to truncate, margins entire or denticulate, apex acuminate to rounded. |
|
| Inflorescences | bracts linear to lanceolate or oblanceolate. |
|
| 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 4-5, spreading or reflexed from base, 1.5-3 × 1-1.5 mm, glabrous or sparsely hirsute; petals 1-3, 1.5-2 × 0.5-1 mm; nectary scales 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 hemispheric to cylindric, 2-8 × 2-3 mm; achenes 1-1.2 × 0.6-0.8 mm, ± tuberculate, glabrous; beak absent or nearly so, to 0.1 mm. |
Ranunculus austro-oreganus |
Ranunculus pusillus |
|
| Phenology | Flowering spring (May). | Flowering spring (Apr–Jun). |
| Habitat | Grassy hillsides | Ditches, ponds, and swamps |
| Elevation | 500 m [1600 ft] | 0-300 m [0-1000 ft] |
| Distribution |
OR
|
AL; AR; CA; DC; DE; FL; GA; IL; IN; KY; LA; MD; MO; MS; NC; NJ; NY; OH; OK; PA; SC; TN; TX; VA; WV
|
| 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 most specimens of Ranunculus pusillus, the heads of achenes are hemispheric to short-ovate and only 2-3 mm. Occasional plants with cylindric heads of achenes 4-6 mm from the Gulf Coast states have been called R. pusillus var. angustifolius. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
| Parent taxa | ||
| Sibling taxa | ||
| Synonyms | R. oblongifolius, R. pusillus var. angustifolius, R. tener | |
| Name authority | L. D. Benson: Amer. Midl. Naturalist 52: 341. (1954) | Poiret: in J. Lamarck et al., Encycl. 6: 99. (1804) |
| Source | FNA vol. 3. | FNA vol. 3. |
| Web links |
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