Flora of the Canadian Arctic Archipelago

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S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, L.J. Gillespie, A.K. Brysting, H. Solstad, and J.G. Harris

Ranunculus arcticus Richardson

English: Birdfoot buttercup,

French: Renoncule arctique,

Inuktitut: Ijuttait niqingit.

Ranunculaceae, Buttercup family.

Published in In Franklin, Narr. Journey Polar Sea, Bot. App. 741, 1823.

Type: Described from Arctic Canada.

Synonymy. Ranunculus affinis R. Br., Chloris Melvill. 7. 1823.

Ranunculus pedatifidus Sm. var. affinis (R. Br.) L.D. Benson, Amer. Midl. Nat. 52: 355. 1954.

Ranunculus pedatifidus Sm. subsp. affinis (R. Br.) Hultén, Ark. Bot., ser. 2, 7, 1: 58. 1968.

Ranunculus pedatifidus Sm. var. leiocarpus (Trautv.) Fernald, Rhodora 19: 138. 1917.

Ranunculus eastwoodianus L.D. Benson, Amer. J. Bot. 27: 804. 1940.

Ranunculus pedatifidus auct., non Sm. 1814.

Vegetative morphology. Plants 8–30(–45) cm high; perennial herbs; caespitose. Only fibrous roots present. Roots slender 0.4–1 mm in diameter. Caudex present (short, erect). Aerial stems erect. Aerial stem trichomes spreading. Leaves heterophyllous (basal leaves long-petioled, cordate to reniform in outline; cauline leaves sessile or short-petioled, the lowermost similar to the basal leaves, the upper merely 3-cleft into linear segments); mainly basal; alternate; marcescent (basal leaves), or dying annually and non-persistent. Petioles 22–35 mm long. Leaf blades simple. Leaf blade bases cordate, or truncate. Leaves not grass-like. Blades 8–15(–38) mm long, 12–20(–48) mm wide (exceptional leaf 45 mm × 65 mm, with petiole 110 mm long, growing on a plant near bird cliffs Aiken 05–056), ovate or reniform (divided into 5–7 linear divisions some of which are lobed), flat, veins palmate. Blade adaxial surface hairy, hairs simple. Blades lobed. Blade margins entire (never toothed). Hydathodes present but inconspicuous. Blade apices acute.

Reproductive morphology. Flowering stems with leaves. Flowers solitary, or in inflorescences. Inflorescences cymose. Flowers per inflorescence (1–)2–3(–7); medium-sized. Sepals conventional; 5; free; 3–5 mm long; 4–6 mm wide; green and purple (abaxially pilose, hairs colourless); herbaceous. Calyx hairy (thinly grey villous). Calyx hairs white or translucent. Calyx teeth without or with few glandular verrucae. Petals conventional; free; 5; yellow; obovate; unlobed; (5–)7–8(–10) mm long; 5–9 mm wide. Stamens 15–25; stamen filaments glabrous. Nectaries present (nectary scale glabrous, forming a pocket, sometimes deeply notched). Receptacle 2–9 mm high (2–3 mm in flower, 7–9 mm in fruit; canescent); surface hairy (canescent, hoary, covered with short fine silvery grey hairs). Ovary carpels 80–100; apocarpous. Stigmas per ovary 1. Placentation parietal. Ovules per ovary 1. Fruit stalk 5–5.5 mm long; dry; an aggregate of achenes; obovate; yellowish; 7–15 mm long; 5–8 mm wide (each achene 2.2–2.7 × 1.8–2.2 mm, beak lanceolate, or subulate, curved, 0.5–1 mm long); glabrous, or hairy (very finely canescent or glabrate); indehiscent. Styles remaining straight. Seeds 1.

Chromosome information. 2n = 28, or 32, or 48.

2n = 28. Sokolovskaya (1958);

2n (4x) = 32. Holmen (1952, Greenland); Zhukova (1966, 1967, 1969, 1980, 1982, northeastern Asia, 1967a, garden material); Johnson and Packer (1968, northwestern Alaska); Zhukova and Tikhonova (1971, Chukotka); Zhukova et al. (1973, northeastern Asia); Göpfert (1974); Scott (1974a, North America, as R. pedatifidus leiocarpus); Krogulevich (1976a, northern Siberia; 1984, Siberia); Zhukova and Petrovsky (1980, western Chukotka); Yurtsev and Zhukova (1982, northern Siberia);

2n (6x) = 48. Böcher and Larsen (1950, Greenland); Hedberg (1967, northern Canada, as R. pedatifidus); Löve and Löve (1982, Arctic Canada); Dalgaard (1989, western Greenland).

Ploidy levels recorded 4x/6x.

Ecology and habitat. Substrates: tundra, slopes, ridges, cliffs, barrens; dry, moderately well-drained areas; rocks, gravel, sand; with low organic content; calcareous. Calcareous gravel, sandy or grassy slopes (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. Uncommon. Arctic, alpine. Arctic islands: Baffin, Ellesmere, Axel Heiberg, Parry islands (Mellville and Emerald), Banks, Victoria, Southampton, Coats.

Northern hemisphere distribution. Circumpolar, or circumboreal (arctic-alpine). Svalbard – Franz Joseph Land, Polar Ural – Novaya Zemlya, Yamal–Gydan, Taimyr – Severnaya Zemlya, Anabar–Olenyok, Kharaulakh, Yana–Kolyma, 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. Ericsson, in Jonsell (2001a, Flora Nordica 2), noted that Ranunculus affinis R. Br. was first described validly in Chloris Melvilliana (published late in 1823). Richardson's R. arcticus, in 'Bot. App.' (from March 1823), predates Brown's R. affinis.

Elven et al. (2003) noted that "Löve and Löve (1975) listed five hexaploid counts for their R. affinis s.s., mostly as arctic. However, they listed numerous tetraploid counts under the name R. wilanderi, all from areas where this local Svalbard endemic of the R. auricomus aggregate (Ericsson, in Jonsell 2001a, Flora Nordica 2) is unknown. It is therefore quite evident that they have 'sorted' their chromosome counts entirely independent of the morphology (and taxonomy), and that R. arcticus occurs with at least two ploidy levels, tetraploid and hexaploid."

The reproductive system of R. arcticus is not known, but agamospermy, as in the related R. auricomus aggregate, cannot be excluded (Böcher and Larsen 1950) [Meddel. Grønl. 147, 6]. Rozanova (1932) [Trudy Peterg. Estestv.-Nauchn. Inst. 8: 19–148], however, found the pollen to be good and found no fruit set after emasculation and pollination with pollen from R. auricomus. It is still difficult to separate plants of the R. arcticus and R. auricomus groups in some areas, especially in northern Russia. Even if some local populations and population groups might be separable on morphological criteria (and could receive names), there is no current circumpolar survey of the variation.

Whittemore (1997) treated this taxon under the name the name Ranunculus pedatifidus var. affinis. He noted that specimens of Ranunculus pedatifidus from southern Siberia, China, and central Asia, including the type specimen, are relatively small and slender, with all the main divisions of the leaf parted into narrow (1.5–2.5 mm wide) segments. American material, including the type of R. affinis, is more robust; the main divisions of the leaf are mostly undivided, and the ultimate segments are broader (2–4 mm wide). Benson (1954) referred all material from Asia and the islands in the Bering Sea to var. pedatifidus. Whittemore indicated other authors who have limited typical pedatifidus to material from temperate Asia and suggested that further comparisons of American and Eurasian material are needed.

Glabrous-fruited forms, first described from Asia, have been called Ranunculus pedatifidus var. leiocarpus (Traūv.) Fernald.

Illustrations. • Close-up of plant: Dorset. Buttercup growing in tundra with Bistorta and fireweed. Nunavut, Baffin Island, Cape Dorset. 4 August, 2005. Aiken. No voucher. • Habitat: Banks Island. Plants growing with Oxytropis borealis in gravel near the top of a pingo. N.W.T., Banks Island, Aulavik National Park. 11 July, 1999. Aiken 99–056. CAN. Scale bar in cm. • Habit: Banks Island. Plants growing on the sides of a gully. N.W.T., Banks Island, Sachs Harbour. 27 July, 1981. Gillett 18883. CAN. • Habitat: Southampton Island. Plants 5–10 cm high growing in gravel among rocks. Nunavut, Southampton Island, Coral Harbour. Aiken and Brysting 01–069. CAN. Photographed by M. Mallory. • Close-up of basal leaves. Plant growing in the shelter of a rock. Note long-petioled leaves, cordate to reniform in outline, at the base. Nunavut, Southampton Island, Coral Harbour. Aiken and Brysting 01–069. CAN. Scale bar in cm. Photographed by M. Mallory. • Habitat. Mass of vigorous plants with yellow flowers at the base of a bird cliff. Nunavut, Baffin Island, Iqaluit. Aiken 02–009b. CAN. • Close-up of plant. Inflorescences in bud and flowering. Note the reddish colour on the outer surface of the sepals. Nunavut, Baffin Island, Iqaluit. Aiken 02–009b. CAN. • Plant with fading petals. Flowers with yellow petals that fade to white with age. Aiken 02–009b. CAN. • Close-up of calyx. Underside of flower showing calyx of five free sepals that are reddish and slightly hairy. Nunavut, Southampton Island, Coral Harbour. Aiken and Brysting 01–069. CAN. • Close-up of plant. Plant in full anthesis in south facing, slightly bird-manured cliff. Norway, Svalbard, Kapp Thordsen. July, 1997. Photograph by R. Elven. Voucher at 0. • Herbarium specimen. Herbarium specimen of a flowering plant showing variation in leaf form. Note the thin upper leaves and the lobed basal leaves. N.W.T., Arctic Coast, Nicholson Island. 15–16 August, 1927. A.E. and R.T. Porsild 2878. CAN 56315. • Close-up of flower. Close-up of flower showing five yellow petals, pre-anthesis yellow anthers, and yellowish spiky styles on greenish carpels. N.W.T., Banks Island, Aulavik National Park. 11 July, 1999. Aiken 99–056. CAN. • 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.

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