Flora of the Canadian Arctic Archipelago
English: Floating buttercup, arctic crowfoot,
French: Renoncule hyperboréale,
Inuktitut: Iquttair niqingita ajjikasingit.
Ranunculaceae, Buttercup family.
Published in Skr. Kiøbenhavnske Selsk. Lærd. Elsk. 10: 458. 1770.
Type: Iceland, leg. Koenig. Holotype: C.
Synonymy. Ranunculus hyperboreus Rottb. var. tricrenatus Rupr.;Beitr. Pflanzenk. Russ. Reiches 2:. 1845.
Ranunculus hyperboreus Rottb. subsp. tricrenatus (Rupr.), Á. Lőve and D. Lőve, Bot. Not. 128: 512. 1975 (1976).
Ranunculus aquatilis L. var. arcticus Durand, Pl. Kan. No.1. App. to E. K. Kane, Arctic Expl. 2nd Grinnell Exp. in Search of Sir John Franklin 1853. 54°55'. 2:1856.
Ranunculus hyperboreus Rottb f. fluitans Porsild, Meddel Grønl. 50: 375. 1912.
Ranunculus hyperboreus Rottb var. turquetilianus Polunin, Bull. Natl. Mus. Canada 94 (Biol. Ser. 24): 211. 1940. pl 6. lower left.
Ranunculus hyperboreus Rottb. subsp. intertextus (Greene) B.M. Kapoor and Á. Lőve, Caryologia 23: 588. 1971.
Ranunculus hyperboreus f. integrescens Savile and Calder, 1952. Type: Chesterfield Inlet, 8 miles S.W. of Settlement. 63°21'N, 90°42'W, D.B.O Savile and C.T. Watts 1464, 16 Aug. 1950. DAO!
Ranunculus hyperboreus f. turquetilianus Savile and Calder, 1952.
Vegetative morphology. Plants 1.2–2 cm high; perennial herbs; not caespitose. Only fibrous roots present. Roots filiform. Ground level or underground stems horizontal; stoloniferous (floating in shallow water); elongate; 0.5–1 mm wide. Caudex absent. Aerial stems erect (rarely, when growing in sand at shore), or prostrate (rooting at the nodes; basal leaves absent). Leaves present; distributed along the stems; alternate; dying annually and non-persistent. Petioles 7–12 mm long. Leaf blades simple. Leaf blade bases cordate, or obtuse. Leaves not grass-like. Blades (3–)4–7(–12) mm long, 8–12(–20) mm wide, reniform, flat, veins palmate. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins flat, blades lobed (deeply 3-lobed, terminal segment entire or crenulate towards the apex). Blade margins entire, with non-glandular hairs. Hydathodes present but inconspicuous. Blade apices rounded.
Reproductive morphology. Flowering stems two or more per plant; with leaves. Flowers solitary. Flowers small. Sepals conventional; 3–4; free; 1–3 mm long (spreading or reflexed from the base); (2–)3–4 mm wide; yellow and brown; scarious. Calyx glabrous. Petals conventional; free; 3–4(–5); yellow; obovate; unlobed; 4–5 mm long; 1–3 mm wide. Stamens 8–12; stamen filaments glabrous. Nectaries present (nectary scale poorly developed; forming a crescent-shaped ridge below the nectary but not covering it). Receptacle 1–1.5 mm high (1 mm in flower, 1.5 mm in fruit); surface glabrous. Ovary carpels 15–20; apocarpous. Styles 0.1–0.2 mm long. Stigmas per ovary 1. Placentation parietal. Ovules per ovary 1. Fruit stalk 4 mm long; dry; an aggregate of achenes; spherical, or ovoid; yellowish; 3–5 mm long; 2–5 mm wide (achenes 1.3–1.7 × 0.8–1.2 mm, glabrous; beak linear, curved, 0.1–0.4 mm long); indehiscent. Styles remaining straight. Seeds 1.
Chromosome information. 2n = 24, or 32.
2n (3x) = 24. Sokolovskaya (1968, northeastern Asia, Koryak);
2n (4x) = 32. Langlet (1936); Böcher (1938a); Sørensen and Westergaard in Löve and Löve (1948, Greenland); Sokolovskaya (1958, 1962, 1963, 1970, northeastern Russia); Sokolovskaya and Strelkova (1960, 1962); Zhukova (1966, 1969, 1980, 1982, northeastern Asia); Mosquin and Hayley (1966, northern Canada); Knaben and Engelskjøn (1967, Norway); Hedberg (1967, northern Canada); Johnson and Packer (1968, northwestern Alaska); Knaben (1968, central Alaska); Taylor and Mulligan (1968, western Canada); Mulligan and Porsild (1969, Yukon); Zhukova and Petrovsky (1971, Wrangel Island); Scott in Löve (1974, North America); Zhukova and Petrovsky (1976, western Chukotka, as subsp. hyperboreus); Krogulevich (1976a, northern Siberia; 1984, Siberia); Zhukova et al. (1977, northeastern Asia); Engelskjøn (1979, Norway); Lavrenko and Serditov (1986, northern Russia); Malakha (1990, northeastern Asia).
Ploidy levels recorded 3x/4x.
Ecology and habitat. Substrates: wet meadows, marshes, along streams; aquatic, imperfectly drained moist areas; silt, clay, till, sand (rarely). Grows on mud near stream margins and ponds, marshes, wet seashores, on muddy substrates, rarely on sand, often on organic substrates. Common in shallow fresh or brackish water, frequently growing among tall sedges and grasses by the edge of ponds (Porsild 1957).
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago widespread. Common. Arctic, alpine. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands (Bathurst, Eglington, Ellef Ringnes, Melivile Prince Charles, Prince Patrick), Cornwallis, Banks, Victoria, Somerset, King William, Southampton, Coats (Melville Peninsula).
Northern hemisphere distribution. Circumpolar, or circumboreal. Northern Iceland, Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, West Chukotka, Wrangel Island (?), South Chukotka, East Chukotka, West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Bay, Ellesmere Land Peary Land, West Greenland, East Greenland.
General notes. Ranunculus hyperboreus subsp. hyperboreus occurs in the Canadian Arctic Archipelago. This and a second subspecies, Ranunculus hyperboreus Rottb. subsp. arnellii Scheutz, represent comparatively clear parapatric entities, that is, subspecies ('hyperboreus' and 'arnellii') with intermediates, e.g., in coastal northern Norway.
Whittemore (1997) noted that specimens from the central and southern Rocky Mountains that have the leaves always cordate and the fruiting heads always 4–5 mm have been distinguished as R. hyperboreus subsp. intertextus. Although Arctic specimens are more variable, they often have shallowly cordate leaf bases and equally large heads of achenes, so segregation of the subspecies seems inappropriate.
Illustrations. • Plant habit: Baffin Island. Close-up of plants growing in mud with leaves divided into three and lobing towards the tips. Note the red horizontal stems. Nunavut, Baffin Island, Iqaluit. 25 July, 1982. J.M. Gillett 19064. CAN. • Habitat: Baffin, Iqaluit gravel. Plants growing erect in damp gravel with mosses and liverworts. Nunavut, Baffin Island, Iqaluit, runoff below Brown building. July, 2005. Aiken and A. Archambault 05–002. CAN. 586920. Photograph by Kathy Thornhill. • Close-up of plants in gravel. Plants growing erect in damp gravel. Nunavut, Baffin Island, Iqaluit, runoff below Brown building. July, 2005. Aiken 05–002. CAN 586920. Photograph by Kathy Thornhill. • Close-up of erect flowering stem. Flowering stem approximately 5 cm high growing erect from plant stranded in shallow water. Nunavut, Baffin Island, Iqaluit. July, 2005. Aiken 05–001. CAN. CAN. 586920. Photograph by Kathy Thornhill. • Close-up of rhizomes. Stems trailing through the water. Nunavut, Baffin Island, Iqaluit. July, 2005. Aiken 05–001. CAN. 586920. Photograph by Kathy Thornhill. • Close-up of leaves and stipule. Plant in early stage of fruit development. Note deeply three-lobed leaves with conspicuous stipule at the junction with the stem. Nunavut, Baffin Island, Iqaluit. July, 2005. Aiken 05–002. CAN. Photograph by Kathy Thornhill. • Close-up of fruit. Various stages of fruit development in apocarpous ovaries forming aggregates of achenes. Nunavut, Baffin Island, Iqaluit. July, 2005. Aiken 05–002. CAN. Photograph by Kathy Thornhill. • Habitat: water Norway. Aquatic plants with few flowers. Note subsp. hyperboreus (our subspecies) has leaves with few dissections. Norway, Nordland, Rodoy, Myken. 21 July, 1986. Photograph by R. Elven. Voucher at TROM. • Close-up of plant. Plant creeping among stones at river margin. Note the leaf shape (subsp. hyperboreus, our subspecies) and the three petals. Norway, Finnmark, Tana, south of Rustefjelbma. July, 1976. Photograph by R. Elven. Voucher at TROM. • Herbarium specimen. Herbarium specimen of a flowering plant with a long horizontal stem. N.W.T., Prince Patrick Island, Mould Bay. 17 July, 1952. S.D. MacDonald 104. CAN 220243. • Arctic Island Distribution.
This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.
Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.
Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa..