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Photo is of parent taxon

western buttercup

Habit Plants usually ± hispid, sometimes glabrous.
Roots

basal, sometimes also nodal, sometimes tuberous.

Stems

erect to reclining, 2-3 mm thick, pilose or glabrous.

erect to decumbent, sometimes stoloniferous, sometimes bulbous-based, without bulbils.

Leaves

basal and cauline, petiolate;

basal deeply parted or compound (except sometimes in R. orthorhynchus var. bloomeri), blades with segments lobed or parted, margins toothed;

cauline deeply parted or compound, similar to basal or with shorter petioles and/or blades with narrower segments (rarely poorly developed in R. fascicularis).

Basal leaf blades

3-parted, ultimate segments elliptic or narrowly elliptic, margins dentate.

Inflorescences

1-50-flowered cymes.

Flowers

sepals 5, 5-7 mm;

petals 5-6, 8-12 × 3-8 mm.

pedicellate;

sepals deciduous soon after anthesis, 5 (sometimes 6 in R. occidentalis var. hexasepalus);

petals always present, yellow, sometimes abaxially reddish, rarely poorly developed;

nectary scale attached basally, free from petal for at least 1/2 its length, forming flap covering nectary (or sometimes attached on 3 sides, forming pocket in R. recurvatus), glabrous, free margin entire;

style present.

Fruits

achenes, 1-locular;

achene body discoid, strongly flattened, 3-15 times as wide as thick, not prolonged beyond seed;

wall thick, not ornamented;

margin low or high narrow ridge or wing;

beak much shorter than achene body.

Achenes

3-3.4 × 2.6-3 mm, glabrous;

beak lanceolate, curved, 1.2-1.4 mm.

2n

= 28.

Ranunculus occidentalis var. brevistylis

Ranunculus sect. Ranunculus

Phenology Flowering spring–summer (May–Aug).
Habitat Coastal and mountain meadows
Elevation 0-1000 m (0-3300 ft)
Distribution
from FNA
AK; AB; BC; YT
[BONAP county map]
Worldwide except lowland tropics
Discussion

Ranunculus occidentalis var. brevistylis may be difficult to distinguish from var. occidentalis; the two have sometimes been combined. The pubescence character distinguishing them is well correlated with geography, however, so I am provisionally maintaining both of them.

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

Species ca. 100 (19 in the flora).

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

Key
1. Petals 2-6 mm, usually no longer than sepals (sometimes longer than sepals in R. uncinatus).
→ 2
1. Petals (6-)7-26 mm (rarely shorter in R. occidentalis and R. canus, in which petals are much longer than sepals).
→ 5
2. Basal leaves simple and lobed or parted.
→ 3
2. Basal leaves compound.
→ 4
3. Receptacle glabrous; base of stem not bulbous; w North America.
R. uncinatus
3. Receptacle hispid; base of stem bulbous, cormlike; e North America.
R. recurvatus var. recurvatus
4. Petals 2-4 × 1-2.5 mm; heads of achenes cylindric, 5-7 mm wide.
R. pensylvanicus
4. Petals 4-6 × 3.5-5 mm; heads of achenes globose to ovoid, 7-10 mm wide.
R. macounii
5. Sepals spreading, sometimes reflexed from base with age.
→ 6
5. Sepals reflexed along well-defined transverse fold 1-3 mm above base.
→ 12
6. Basal leaves deeply parted or dissected, ultimate segments linear to broadly linear, margins entire (occasionally a lobe reduced to large tooth); Rocky Mountains.
R. acriformis var. acriformis
6. Basal leaves variously parted or compound but not as above, segments seldom linear, margins toothed; widespread.
→ 7
7. Leaf blades simple, 3-5-parted or -divided.
→ 8
7. Leaf blades 3-5-foliolate.
→ 9
8. Basal leaf blades pentagonal in outline; beak of achene 0.2-1 mm; widespread.
R. acris
8. Basal leaf blades cordate to reniform in outline; beak of achene 1.6-2 mm; Mackenzie Delta to ne Alaska.
R. turneri
9. Tuberous roots present.
→ 10
9. Tuberous roots absent.
→ 11
10. Petals 10-22; c Texas.
R. macranthus
10. Petals 5(-7); widespread, e North America.
R. fascicularis
11. Beak of achene curved, 0.8-1.2 mm; stems decumbent to creeping.
R. repens
11. Beak of achene straight or somewhat curved, 0.8-2.6 mm; stems erect to decumbent.
R. hispidus
12. Petals 8-22; Pacific Coast, Arizona, Texas.
→ 13
12. Petals 5-7; widespread.
→ 17
13. Tuberous roots absent; beak of achene lanceolate to deltate-apiculate, curved, 0.2-1.6 mm; California to British Columbia.
→ 14
13. Tuberous roots present; beak of achene subulate, straight, (1.8-)2-4 mm (but sometimes deciduous); Texas, Arizona.
→ 16
14. Achenes 3.4-4.2 mm, beak deltate or lance-deltate; Transverse Ranges, s California.
R. canus var. ludovicianus
14. Achenes 1.8-3.2 mm, beak lanceolate; California to British Columbia.
R. californicus
15. Beak of achene 1.2-1.6 mm; sepals 5-6; Queen Charlotte Islands, British Columbia.
R. occidentalis var. hexasepalus
15. Beak of achene 0.2-0.8 mm; sepals 5; California, Oregon, Mexico.
R. californicus
16. Petals 2-5 mm wide; achenes 2-2.4 mm wide, margins forming ribs or narrow wings 0.1-0.4 mm wide; sepals always reflexed; Arizona, trans-Pecos Texas.
R. fasciculatus
16. Petals 4-9 mm wide; achenes 2.8-3.4 mm wide, margins forming narrow ribs 0.4-0.6 mm wide; sepals spreading or weakly reflexed; Edwards Plateau, Texas.
R. macranthus
17. Receptacle glabrous; basal leaves 3-parted or -foliolate, segments or leaflets linear to cuneate.
→ 18
17. Receptacle hispid; basal leaves usually pinnately 3-7-foliolate (sometimes merely 3-parted with orbiculate to ovate segments in Ranunculus orthorhynchus var. bloomeri).
→ 21
18. Beak of achene deltate or lance-deltate, curved; Sacramento Valley, California.
R. canus var. canus
18. Beak of achene lanceolate to lance-subulate, straight or curved; widespread.
→ 19
19. Basal leaves deeply 3-divided, segments again deeply parted, ultimate segments linear or nearly so; Rocky Mountains.
R. acriformis var. montanensis
19. Basal leaves deeply 3-parted to 3-foliolate, margins of segments or leaflets toothed or shallowly lobed, ultimate lobe triangular or broadly lanceolate; Pacific Slope.
→ 20
20. Petals yellow on both surfaces; widespread.
R. occidentalis
20. Petals reddish abaxially; sw Oregon.
R. austro-oreganus
21. Beak of achene oblong or triangular, curved, 0.2-0.8 mm; introduced weeds.
→ 22
21. Beak of achene lanceolate or subulate, straight or somewhat curved (sometimes tip weakly hooked in R. pacificus), (0.8-)1-3.8(-4.8) mm; native.
→ 23
22. Base of stem bulbous, cormlike; petals 9-13 × 8-11 mm.
R. bulbosus
22. Base of stem not bulbous; petals 7-10 × 4-8 mm.
R. sardous
23. Stems decumbent, sometimes rooting at nodes; e North America.
R. hispidus var. nitidus
23. Stems erect to decumbent, never rooting at nodes; w North America.
→ 24
24. Beak of achene 1-1.8 mm; leaflets lobed; Alaska panhandle.
R. pacificus
24. Beak of achene 2-3.8(-4.8) mm (1.8-2.2 mm in var. bloomeri, with unlobed leaflets); throughout w North America.
R. orthorhynchus
Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Ranunculus > Ranunculus occidentalis Ranunculaceae > Ranunculus > subg. Ranunculus
Sibling taxa
R. occidentalis var. dissectus, R. occidentalis var. hexasepalus, R. occidentalis var. howellii, R. occidentalis var. nelsonii, R. occidentalis var. occidentalis, R. occidentalis var. ultramontanus
Subordinate taxa
R. acriformis var. acriformis, R. acriformis var. montanensis, R. acris, R. austro-oreganus, R. bulbosus, R. californicus, R. canus var. canus, R. canus var. ludovicianus, R. fascicularis, R. fasciculatus, R. hispidus, R. hispidus var. nitidus, R. macounii, R. macranthus, R. occidentalis, R. occidentalis var. hexasepalus, R. orthorhynchus, R. pacificus, R. pensylvanicus, R. recurvatus var. recurvatus, R. repens, R. sardous, R. turneri, R. uncinatus
Synonyms R. occidentalis subsp. insularis R. section Chrysanthe
Name authority Greene: Pittonia 3: 14. (1896) Linnaeus
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