Ranunculus adoneus
Ranunculus sect. Epirotes
alpine buttercup
slender, 0.8-1.4 mm thick.
basal, sometimes tuberous.
erect from large caudices, 9-25 cm, glabrous, each with 1-3 flowers.
erect, not bulbous-based, without bulbils.
basal and cauline, simple or compound;
basal leaves petiolate, blades variously divided, unlobed to deeply parted, compound, or filiform-dissected, segments undivided or again lobed or parted, margins entire or crenate, never serrate;
cauline leaves sessile to nearly sessile or sometimes with much shorter petioles than basal leaves, blades lobed to compound or dissected (rarely unlobed in R. macauleyi and R. glaberrimus).
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.
1-50-flowered cymes.
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.
pedicellate;
sepals deciduous soon after anthesis, 5;
petals yellow (rarely absent in R. pedatifidus);
nectary scale joined with petal on 3 sides, forming pocket enclosing nectary (sometimes with apex free, forming flap shorter than pocket), glabrous or setose, free margin entire or fringed;
style present.
achenes, 1-locular;
achene body thick-lenticular or asymmetrically thick-lenticular to compressed-globose, 1.2-2 times as wide as thick, not prolonged beyond seed;
wall thick, smooth;
margin low narrow ridge, often inconspicuous;
beak much shorter than achene body.
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.
n = 16.
Ranunculus adoneus
Ranunculus sect. Epirotes
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.)
Species ca. 70 (22 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Abaxial surface of sepals with dense brown pubescence. | → 2 |
1. Abaxial surface of sepals glabrous or with colorless hairs. | → 4 |
2. Basal leaf blades narrowly elliptic to lanceolate or oblanceolate; s Rocky Mountains. | R. macauleyi |
2. Basal leaf blades orbiculate to reniform; Canadian Rocky Mountains and Arctic. | → 3 |
3. Receptacle brown-pilose; basal leaf blades usually shallowly lobed, or unlobed with crenate margins. | R. sulphureus |
3. Receptacle glabrous; basal leaf blades 3-parted. | R. nivalis |
4. Basal leaves deciduous before anthesis; nectary scale ciliate, petals 2–3 times as long as wide. | R. arizonicus var. arizonicus |
4. Basal leaves persistent; nectary scale glabrous, (glabrous or ± pilose in R. cardiophyllus and R. glaberrimus, which have petals 1–1.5 times as long as wide). | → 5 |
5. Some or all basal leaf blades unlobed. | → 6 |
5. All basal leaf blades lobed or parted. | → 14 |
6. Basal leaf margins entire or with 3 broad shallow rounded teeth; heads of achenes globose, 6–20mm wide. | R. glaberrimus |
6. Basal leaf margins either crenate to crenate-lobulate, with more than 5 rounded teeth, or innermost teeth lobed or divided; heads of achenes usually ovoid to cylindric (sometimes globose and 3–8 mm wide). | → 7 |
7. Petals 1–3.5 mm. | → 8 |
7. Petals 4–18 mm. | → 10 |
8. Stems villous, sometimes sparsely so; receptacle glabrous; base of some roots ± swollen and tuberous, usually 1–2 mm thick; leaf base usually obtuse or truncate. | R. micranthus |
8. Stems glabrous; receptacle pilose, sometimes sparsely so; base of roots never much swollen, 0.2–1.5 mm thick; leaf base ± cordate. | → 9 |
9. Sepals hispid; achene beak 0.6–1 mm. | R. allegheniensis |
9. Sepals glabrous; achene beak 0.1–0.2 mm. | R. abortivus |
10. Leaf blades wider than long; e of Great Plains, not in Great Lakes area. | → 11 |
10. Leaf blades at least as long as wide; Great Lakes area and Great Plains w to Great Basin. | → 12 |
11. Pedicels glabrous (see also R. escholtzii with lobed leaves); se United States. | R. harveyi var. harveyi |
11. Pedicels pubescent, sometimes sparsely so; e Canada. | R. allenii |
12. Sepals 5–8 × 3–7 mm; nectary scale ciliate, sometimes glabrous; leaf base cordate to broadly obtuse. | R. cardiophyllus |
12. Sepals 3–6× 1.5–3mm; nectary scale glabrous; leaf base obtuse or acute to rounded. | → 13 |
13. Basal leaf blades ovate, obovate, or orbiculate; heads of achenes cylindric, 7–17 mm; achene beak 0.4–2 mm; Rocky Mountains, Great Basin, and Black Hills. | R. inamoenus |
13. Basal leaf blades ovate to rhombic; heads of achenes depressed-globose, 4–6 mm; achene beak 0.2– 0.3 mm; n Great Plains and eastward. | R. rhomboideus |
14. Basal leaf blades dissected into linear segments. | → 15 |
14. Basal leaves at most 1×-divided, segments not linear. | → 16 |
15. Roots slender, 0.8–1.4 mm thick; achene beak 1.2–1.7 mm. | R. adoneus |
15. Roots 2–3 mm thick; achene beak 0.8–1.5 mm. | R. triternatus |
16. Some roots clavate and tuberous, 2.5–5 mm thick; basal leaf blades deeply divided into 3 oblanceolate segments. | R. jovis |
16. Roots not clavate or tuberous, 0.1–1.6 mm thick; leaves various but not as above. | → 17 |
17. Petals 7–15 mm. | → 18 |
17. Petals 1–8 mm. | → 20 |
18. Pedicels glabrous. | R. eschscholtzii |
18. Pedicels pubescent. | → 19 |
19. Heads of achenes globose to short-ovoid; basal leaves 3-parted with segments again lobed or parted, margins toothed; Greenland. | R. auricomus |
19. Heads of achenes cylindric; basal leaves pedately (5–)7(–9)-parted or -divided, segments sometimes again lobed, margins never toothed; throughout n North America. | R. pedatifidus var. affinis |
20. Flowering stems 0.6–3.5 cm (sometimes longer in fruit); petals 1–3.5 mm. | R. pygmaeus |
20. Flowering stems (1–)4–15(–27) cm; petals 3–8 mm. | → 21 |
21. Petals 6–16 mm; beak of achene straight, 0.6–1.8 mm; pedicels glabrous. | R. eschscholtzii |
21. Petals 4–8 mm; beak of achene straight or curved, 0.3–0.7 mm; pedicels glabrous or pilose. | → 22 |
22. Base of basal leaves obtuse; petals 5–8 mm; arctic Alaska, Canada, and Greenland. | R. sabinei |
22. Base of basal leaves nearly cordate to truncate; petals 4–5 mm; Alaska, Yukon, and Rocky Mountains. | R. gelidus |
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