Ranunculus
Ranunculus sect. Epirotes
buttercup, crowfoot, renoncule, water-buttercup
basal, sometimes tuberous.
erect, not bulbous-based, without bulbils.
blade reniform to linear, margins entire, crenate, or toothed.
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).
terminal or axillary, 2-50-flowered cymes to 25 cm or solitary flowers;
bracts present or absent, small or large and leaflike, not forming involucre.
1-50-flowered cymes.
bisexual, radially symmetric;
sepals sometimes persistent in fruit, 3-5(-6), green or sometimes purple, yellow, or white, plane (base saccate in R. ficaria), oblong to elliptic, ovate, or lanceolate, 1-15 mm;
petals 0-22(-150), distinct, yellow, rarely white, red, or green, plane, linear to orbiculate, 1-26 mm;
nectary present, usually covered by scale;
stamens (5-)10-many;
filaments filiform;
staminodes absent between stamens and pistils;
pistils 4-250, simple;
ovule 1 per ovary;
style present or absent.
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, rarely utricles, aggregate, sessile, discoid, lenticular, globose, obovoid, or cylindric, sides sometimes veined;
beak present or absent, terminal, straight or curved, 0-4.5 mm.
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.
= 7, 8.
Ranunculus
Ranunculus sect. Epirotes
Species about 300 (76 in the flora).
Most Ranunculus species are poisonous to stock; when abundant, they may be troublesome to ranchers. A few species with acrid juice were formerly used as vesicatories. The genus is badly in need of biosystematic work. Apomixis and interspecific hybridization occur in several Old World groups of buttercups; some of the taxonomic complexity of the New World species probably results from these processes.
Considerable disagreement exists among authors on the proper generic and infrageneric classification of Ranunculus. Most of the subgenera accepted here have been treated as separate genera at one time or another. All recent studies have been based on local or continental floras, however, and classifications proposed for one region may not work for the plants of other regions. Like most North American workers, I have followed the generic and infrageneric classification of L. D. Benson (1948), who gave by far the most thorough and best documented study of the problem. The genus and its subdivisions should be studied on a worldwide basis.
(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. All leaves simple and unlobed. | → 2 |
1. Some or all leaves simple and lobed, or compound. | → 9 |
2. Cauline leaves absent or scalelike; sepals deciduous or persistent. | → 3 |
2. Cauline leaves present, well developed; sepals deciduous. | → 5 |
3. Petals 5; achene beak 0.1-0.2 mm; plants stoloniferous, without caudices. | Halodes (Ranunculus cymbalaria) |
3. Petals 8-18; achene beak 0.8-1.4 mm; plants not stoloniferous, stems erect from short caudices. | → 4 |
4. Leaf blades undivided, margins entire or serrulate; sepals persistent in fruit; petals 7-12 mm. | Oxygraphis (Ranunculus kamtschaticus) |
4. Leaf blades shallowly lobed, margins crenate; sepals deciduous; petals 2-4 mm | Pseudaphanostemma (Ranunculus hystriculus) |
5. Tuberous roots present; flowers yellow; sepals 3. | Ficaria (Ranunculus ficaria) |
5. Tuberous roots absent (roots thickened proximally in some 5-sepaled species of sect. Flammula); flowers yellow, white, or pink. | → 6 |
6. Achenes 4.2-5.2 mm, achene body prolonged beyond seed as corky distal appendage; sepals 3, 6-10 mm; petals white to pink. | Pallasiantha (Ranunculus pallasii) |
6. Achenes 0.8-2.8 mm, achene body not prolonged beyond seed; sepals (3-)4-5, 1.5-12 mm; petals yellow. | → 7 |
7. Sepals covered with dense brown pubescence; distal leaves and bracts apically 3-crenate or shallowly 3-lobed, otherwise undivided. | Epirotes (Ranunculus macauleyi) |
7. Sepals glabrous or with colorless hairs; distal leaves simple and undivided. | → 8 |
8. Achene wall papery, longitudinally ribbed; leaf apex broadly rounded to truncate, margins crenate. | Halodes (Ranunculus cymbalaria) |
8. Achene wall thick, not ornamented, smooth (sometimes pubescent); leaf apex acuminate to rounded-obtuse, margins entire or finely toothed. | sect. Flammula |
9. Leafy stems creeping and rooting at nodes or floating in water, then rootless. | → 10 |
9. Leafy stems erect or if decumbent rooting only at base, never floating. | → 14 |
10. Leaves 3-foliolate. | sect. Ranunculus |
10. Leaves simple, lobed to filiform-dissected or occasionally undivided. | → 11 |
11. Achene body prolonged beyond seed as corky distal appendage; sepals 3, petals 5-11. | → 12 |
11. Achene body not prolonged beyond seed; either sepals 5 or sepals 3-4 and petals also 3-4. | → 13 |
12. Leaf blade as wide as long, ternately divided to base. | Coptidium (Ranunculus lapponicus) |
12. Leaf blade much longer than wide, unlobed or lobed. | Pallasiantha (Ranunculus pallasii) |
13. Petals white or white with yellow claws; achenes with strong coarse wrinkles. | subg. Batrachium |
13. Petals yellow; achenes smooth (faintly wrinkled in R. sceleratus var. sceleratus). | sect. Hecatonia |
14. Petals pure red, or white when immature; fruits winged achenes or utricles. | subg. Crymodes |
14. Petals yellow, rarely also with some red pigmentation abaxially, or greenish yellow; fruits achenes, rarely winged. | → 15 |
15. Cauline leaves absent or scalelike, tuberous roots absent; leaves sometimes deeply parted or dissected, never compound. | → 16 |
15. Cauline leaves present, simple, lobed or dissected, or compound (rarely reduced to scales in R. fascicularis with tuberous roots and 3-5-foliolate leaves). | → 18 |
16. Plants villous; sepals 3-6 × 1-2 mm, persistent in fruit; fruit wall firm, smooth, beak much longer than achene body. | Ceratocephala (Ranunculus testiculatus) |
16. Plants glabrous; sepals 6-13 × 3-7 mm, deciduous in fruit; fruit wall thin, veined, beak much shorter than achene body. | → 17 |
17. Leaves shallowly 5-7-lobed; petals inconspicuous, 2-4 mm. | Pseudaphanostemma (Ranunculus hystriculus) |
17. Leaves 3-5-parted; petals showy, 8-12 mm. | Arcteranthis (Ranunculus cooleyae) |
18. Style absent, stigma sessile; achene margins thick and corky; emergent aquatic, sometimes also found on very wet soil. | Hecatonia (Ranunculus sceleratus) |
18. Style present; achene margins not corky; in various habitats but rarely aquatic. | → 19 |
19. Achene wall thin, longitudinally striate; scale of nectary reduced to low ridge, not covering nectary. | Cyrtorhyncha (Ranunculus ranunculinus) |
19. Achene wall thick, smooth, papillose, or spiny; scale of nectary well-developed flap or pocket completely covering nectary. | → 20 |
20. Achenes thick-lenticular or asymmetrically thick-lenticular to compressed-globose, 1.2-2 times as wide as thick; nectary scale joined with petal on 3 sides, forming pocket enclosing nectary (sometimes with apex free, forming flap shorter than pocket); basal leaves various, unlobed to deeply divided, margins entire to crenate but never at all serrate. | sect. Epirotes |
20. Achenes strongly flattened, at least 3-15 times as wide as thick; nectary scale free from petal for at least 1/2 its length, thus forming free scale over nectary (scale sometimes free for less than 1/2 its length in R. recurvatus, with serrate to crenate-serrate leaf margins); basal leaves always deeply lobed or compound (except sometimes in R. marginatus and R. orthorhynchus), margins various. | → 21 |
21. Achenes papillose or spiny (sometimes smooth in R. sardous); flowers small, petals 1-6 mm, scarcely longer than sepals, sometimes absent (larger and much longer than sepals in R. sardous). | sect. Echinella |
21. Achenes smooth, glabrous or pubescent; flowers small to large, petals always present, 2-22 mm. | sect. Ranunculus |
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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