Ranunculus L.
Perennial, sometimes annual, terrestrial or aquatic herbs; roots fibrous or swollen, sometimes arising from a stout or bulbous rootstock. Lvs usually alternate, rarely opposite, basal and cauline, simple or variously divided to 2-pinnatisect. Fls solitary or in lax leafy cymes; involucre 0. Sepals green, (3)-5-(7). Petals (0)-5-(12 or more), usually yellow, sometimes white, brown or reddish; nectaries near base of petal, 1-(3), pit-like, covered by a scale or naked. Stamens few to many, spiralled. Carpels few to many, with 1 ovule. Achenes few to many; style neither greatly elongated nor feathery. Receptacle glabrous or hairy, globular or cylindric.
SYNOPSIS
- I. Subgen. BATRACHIUM.
- Lvs mostly cauline, usually some or all divided into capillary segments. Petals white, rarely yellow; nectary a lunate or circular pit. Achenes transversely wrinkled. Aquatic plants.
- A. Sect. BATRACHIUM:
- II. Subgen. RANUNCULUS.
- Lvs mostly basal, divided into broad or narrow, but never capillary, segments. Petals yellow, rarely white or reddish; nectary a naked pit or pocket or covered with a scale. Achenes not transversely wrinkled, often flattened. Mostly terrestrial.
- B. Sect. ECHINELLA.
- Roots fibrous. Sepals 5; petals usually 5. Nectary scale entire, truncate, attached laterally or free to base. Achenes beaked, bordered; face bearing spines, hooked hairs, or tubercles:
- 2. * arvensis6. * muricatus8. * parviflorus10. * sardous12. * sessiliflorus
- C. Sect. EPIROTES.
- Roots fibrous. Sepals 5; petals 5-15-(25). Nectary usually naked, solitary or (2)-3 together. Achenes long-beaked, not bordered or flattened, rarely winged; face smooth, hairy or glabrous.
- 1.
- Tufted alpines with stout rhizomes (treated in detail by Fisher, op. cit.)
- (i)
- Petals white:
- 19. buchananii33. lyallii
- (ii)
- Petals yellow
- a.
- b.
- 2.
- Lowland to alpine, often subaquatic; rosettes tufted on slender stolons or rhizomes:
- 14. acaulis16. amphitrichus17. biternatus25. glabrifolius32. limosella34. macropus
- D. Sect. FICARIA.
- Some roots tuberous, others fibrous. Sepals 3; petals 8-12. Nectary scale entire, free. Achenes with minute beak, barely compressed, keeled, glabrous or hairy:
- 4. * ficaria
- E. Sect. FLAMMULA.
- Roots fibrous. Sepals 5; petals 5. Nectary scale entire, free. Achenes with very short beak, slightly compressed, glabrous or tuberculate:
- 5. * flammula7. * ophioglossifolius
- F. Sect. HECATONIA.
- Roots fibrous. Sepals 3-5; petals 3-5. Nectary scale forked or surrounding the nectary. Achenes small, glabrous, barely compressed, very numerous in cylindric heads; beak very short:
- 11. * sceleratus
- G. Sect. RANUNCULUS.
- Roots fibrous. Sepals 5; petals usually 5. Nectary scale entire or retuse, usually free to base. Achenes beaked, usually bordered, usually flattened; face smooth, hairy or glabrous.
- 1.
- Tufted, never stoloniferous, rarely producing offset daughter rosettes
- (i)
- Nectary at base of petal, with broad scale:
- 1. * acris3. * bulbosus15. altus38. multiscapus43. reflexus51. urvilleanus
- (ii)
- Nectary at base of limb, with narrow scale
- a.
- Stem 1-flowered, leafless:
- 18. brevis35. maculatus42. recens44. royi
- b.
- Stem 1-3-(10)-flowered, with 1 or more bracts:
- 24. foliosus31. kirkii37. mirus48. stylosus49. subscaposus
- 2.
- Stoloniferous
- (i)
- Lamina divided into stalked leaflets:
- 9. * repens36. membranifolius50. ternatifolius
- (ii)
- Lamina lobed but not divided to base:
- 20. carsei21. cheesemanii47. simulans
Key
8
Lvs completely glabrous; petiole flattened, (3)-10-20 mm wide; achene beak 2-3× length of body
Lvs usually with dense spreading hairs, rarely with only a few hairs on margin; petiole terete, < 5 mm wide; achene beak 0.4-1.5× length of body
11
Lvs glabrous or with sparse scattered hairs; rhizome short, ascending, subterranean; lamina shallowly 3-5-(7)-lobed, 2-8 cm diam.
Lvs with dense soft hairs; rhizome long, trailing, partly exposed on soil surface; lamina 1-2-ternatifid, 1.5-3 cm diam.
14
Lamina with 3-5 blunt teeth or shallow blunt entire lobes; petals fugaceous; achene body 2-2.5 mm long
Lamina usually 3-fid to c. 1/2 way; lobes ± coarsely toothed at apex; petals persistent; achene body 1.5-1.8 mm long
A
Lvs spathulate, entire or 3-fid, dark or brownish green
var. lacustris
Lvs ovate to orbicular, 3-lobed to c. 1/2 way and again crenate or toothed, pale green
var recens
17
Lamina with scattered hairs especially on margins, or glabrous, 3-lobed; lobes entire; peduncles always glabrous at the extreme tip; achenes 15-25
Lamina with dense covering of hairs, 3-5-lobed; lobes toothed or crenate; peduncles with dense hairs throughout; achenes 25-35
20
Nectary at base of petal, covered by a broad scale; achene beak 0.5-1 mm long; scapes stiffly erect
Nectary > 1 mm from base of petal, covered by a slender scale; achene beak c. 0.5 mm long or less; scapes ascending
A
Leaflets deeply incised, glabrous except for edges of lf sheaths; segments 5-7-lobed
subsp haastii
Leaflets simple, coarsely and obtusely toothed, sparingly covered in silky hairs beneath, especially near insertion of petioles; segments with deeply crenate or toothed margins
subsp. piliferus
26
Peduncles glabrous, rarely with a few very sparse stiff hairs or fls sessile; basal lvs with narrow-linear or narrow-cuneate segments
Peduncles with very slender hairs; basal lvs with oblanceolate or broader segments, but stem lvs sometimes with linear segments
27
Lvs all basal, tufted at tips of long stout trailing rhizomes which are partly exposed on ground surface; lamina 10-20 mm diam.
Lvs basal and cauline on erect stems; rhizome short, underground; lamina of basal lvs 50-150 mm diam.
28
Petioles (2)-3-4-(5) mm diam.; laminae ± constant in depth of dissection; petals emarginate
Petioles 1-2-(3) mm diam.; laminae highly variable in depth of dissection on one plant; petals rounded at apex
29
Petals white with yellow base; lvs finely divided into filiform segments; achenes transversely rugose
Petals yellow or 0; lf segments linear or lanceolate or broader, but never filiform; achene either ± smooth or punctate to spiny, never transversely rugose
31
Fls and frs sessile or on pedicels < 5 mm long; fls < 5 mm diam.; receptacle glabrous
36
Lf segments divided to base, usually into stalked subsegments; pedicels 1-(2) cm long; achenes 5-15-(20)
37
Fls < 1 cm diam.; sepals reflexed; pedicel hairs usually patent or erecto-patent; achenes 2-3 mm long including the 0.5-1 mm long beak
Fls > 1.5 cm diam.; sepals spreading; pedicel hairs appressed; achenes 3-4.5 mm long including the 1-1.5 mm long beak
39
Lf lobes divided to at least 1/2 way, and toothed again; petiole fistular; fls 12-15-(20) mm diam.; achene beak 1.5-2 mm long
Lf lobes entire to shallowly toothed or lobed; petiole solid; fls 5-12 mm diam.; achene beak 0.5-1 mm long
40
Lf lobes obovate, entire or bluntly toothed or shallowly lobed; apex of terminal lobe rounded or broadly obtuse; achene beak straight (N., S., St., Ch., A.)
Lf lobes obtriangular or cuneiform, sharply toothed; apex of terminal lobe acute; achene beak recurved (M.)
41
Plants usually > 7 cm tall, tufted; petiole stout; lamina broader than long, (1.5)-2-4 cm wide; fls 10-15 mm diam.; achenes 15-50
Plants usually < 10 cm tall, creeping; petiole slender; lamina as broad as long, 1-2 cm wide; fls 7-12 mm diam.; achenes 10-30
43
Lvs pinnate to 2-pinnatifid to 2-pinnate; lamina often glabrous but petiole and midrib with silky hairs, especially at bases of pinnae
Lvs 1-2-ternate, 2-ternatifid, or palmate; lamina glabrous or hairy, if glabrous then petiole glabrous also
45
Lvs not pitted, apart from grooves over veins; scapes > lvs at flowering; nectary gland partly enclosed by a basal flap or scale; peduncle erect at fruiting
Lvs irregularly pitted with shallow brown depressions distinct from reticulated grooves over veins; scapes < lvs at flowering; nectary gland without flap or scale; peduncle recurved at fruiting
Fls sessile or shortly stalked but peduncle elongating at fruiting; achenes very numerous; petals sparsely bristly beneath
52
Lvs stiff and brittle with sparse stiff hairs across lamina; scapes < 1 cm tall; achenes brick red; beak hooked, c. 0.5 mm long
42.recens var recens
Lvs flexible with soft hairs chiefly concentrated into penicillate tufts at segment tips; scapes at least 2 cm tall; achenes brown or greenish; beak almost straight, at least 3 mm long
53
Nectary very near base of petal; achenes 4-6-(10) per head, 4-5 mm long including the 2-2.5 mm long, ± straight, beak
Nectary 1 mm or more from base of petal; achenes 30-60 per head, 2.5-4 mm long including the 0.5-1 mm long, usually curved, beak
56
Stem lvs and fls alternate; pedicels sulcate; nectary basal, covered by a very short broad scale
Stem lvs and fls opposite or whorled; pedicels terete; nectary 1 mm or more from base of petal, covered by a small triangular scale
59
Achene body 2.5-3 mm long, dark bronze or purplish brown when ripe; achenes 30-50 in globose heads
Achene body 1.5-2 mm long, pale buff with dark beak; achenes (40)-60-100 in ovoid heads
60
Rootstock swollen, bulbous; middle leaflet stipitate; fls 15-25 mm diam.; achenes 20-40 in globose heads, strongly flattened and bordered, 2.5-3 mm long
Rootstock slender; middle lf lobe not stipitate; fls 6-10 mm diam.; achenes (100)-200-400 or more in elongated cylindric heads, weakly flattened, not bordered, c. 1 mm long
KEY TO WEEDY SPP.
R. foliosus is the only native sp. in this key. It has been collected in weedy habitats only rarely.
Key
5
Lamina of stem lvs linear to lanceolate, cuneate, simple, never lobed, weakly toothed, with closely appressed hairs or glabrous
Lamina of stem lvs ovate to ± circular, truncate to cordate at base, divided to at least 1/2 way and crenate or toothed, with erecto-patent to spreading hairs
6
Fls > 12 mm diam.; lvs divided into 3 separate stalked leaflets; achenes tuberculate near margin
7
Fls and frs sessile or on peduncles < 5 mm long; achenes (1)-3-6, 1.5-2 × 1-1.3 mm
11
Sepals reflexed; lvs glabrous; achenes c. 1 mm long, in cylindric heads of 100-700
13
Lvs ovate to deltoid, deeply cordate; fls 30-50 mm diam.; roots both fibrous and swollen; sepals 3; petals 8-15
Lvs linear to lanceolate, cuneate; fls 10-15 mm diam.; roots all fibrous; sepals 5; petals 5
400 spp., cosmopolitan, mostly temperate. Native spp. 40, naturalised 13.
Most of the native alpine spp. were treated in a detailed monograph by Fisher, F. J. F., The Alpine Ranunculi of New Zealand (1965). However, the taxonomy of those native spp. not treated by Fisher still is in need of detailed revision. Some changes have been made for this treatment, most of them nomenclatural. A few distinctive new spp. have been recognised, but some complexes (e.g., R. foliosus and its allies) have not been critically studied.
Chromosome numbers were reported by Hair, J.B., New Zealand J. Bot. 21: 3-7 (1983).
The shapes described for lvs below are the outline of the lamina; dissection of the lamina is treated separately. For this large genus, a synopsis, general key, and key to weedy spp. are provided.
