Flora of the Canadian Arctic Archipelago
English: Dwarf buttercup, pygmy buttercup,
French: Renoncule nivale, renoncule naine.
Ranunculaceae, Buttercup family.
Published in Fl. Lapp., 157. 1812.
Type: Sweden: Lapponia Lulensis ad Kajsats prope Virihjaur, 04.08.1807, leg. Wahlenberg, selected by Moberg and Nilsson, Nord. J. Bot. 11: 295. 1991. Lectotype: UPS.
Vegetative morphology. Plants 5–14 cm high (to 35 mm tall on continental North America); perennial herbs; caespitose. Only fibrous roots present. Roots slender, 0.1–0.6 mm thick. Ground level or underground stems absent. Caudex present (simple, non-fibrous). Aerial stems erect. Aerial stem trichomes appressed, or spreading. Leaves heterophyllous; mainly basal; alternate; dying annually and non-persistent. Petioles 20–27 mm long. Leaf blade bases cordate, or truncate. Blades 5–10 mm long, (6–)8–13 mm wide, triangular (fan-shaped or semi-circular), flat, veins palmate. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blades lobed (at least the lateral segments lobed again). Blade margins entire, with non-glandular hairs. Hydathodes present but inconspicuous. Blade apices obtuse, or rounded.
Reproductive morphology. Flowering stems with leaves (1–2), or without leaves. Flowers solitary, or in inflorescences. Inflorescences cymose (if applicable). Flowers per inflorescence 1, or 2; medium-sized. Sepals conventional; 5; free; 1.2–1.6 mm long; (2–)3–4(–5) mm wide; yellow and brown; scarious. Calyx hairy (sparsely so on the back). Calyx hairs white or translucent. Petals conventional; free; 5; yellow (pale); obovate; unlobed; 2.5–4 mm long; 1.5–3 mm wide. Stamens 15–25; stamen filaments glabrous. Nectaries present (nectary scale forming a pocket; glabrous). Receptacle 1–2 mm high (1 mm in flower, 1.5–2 mm in fruit; glabrous); surface glabrous. Ovary carpels 45–55; apocarpous. Stigmas per ovary 1. Placentation parietal. Ovules per ovary 1. Fruit dry; an aggregate of achenes; obovate; yellowish; 2.5–7 mm long; 2.5–5 mm wide (achenes 0.8–1.2 × 0.8–1 mm glabrous, beack subulate, straight or curved, 0.3–0.7 mm); indehiscent. Styles remaining straight. Seeds 1 (per follicle).
Chromosome information. 2n = 16.
2n (2x) 16. Langlet (1932, northern Europe); Flovik (1936, 1940, Svalbard); Böcher (1938a); Sokolovskaya and Strelkova (1941, northern Russia, Kolguev, 1960); Löve and Löve (1956, Iceland); Jørgensen et al. (1958, Greenland); Sokolovskaya (1958, 1962); Zhukova (1965b, Wrangel Island; 1969, northeastern Asia); Hedberg (1967, northern Canada); Knaben and Engelskjøn (1967, Norway); Johnson and Packer (1968, northwestern Alaska); Zhukova and Tikhonova (1971, 1973, Chukotka); Zhukova et al. (1973, northeastern Asia); Packer and McPherson (1974, northern Alaska); Krogulevich (1976a, northern Siberia; 1984, Siberia); Zhukova et al. (1977, northeastern Asia); Engelskjøn (1979, Norway); Zhukova (1980, 1982, northeastern Asia); Dawe and Murray in Löve (1981d, Canada, Yukon); Zhukova and Petrovsky (1987b, northeastern Asia); Baltisberger and Huber (1987, Norway); Lavrenko et al. (1989, northern Russia); Murray and Kelso (1997, western Alaska). Several more southern counts.
Ploidy levels recorded 2x.
Ecology and habitat. Substrates: wet meadows, snow patches (screes, polar deserts, burrows and bird cliffs); imperfectly drained moist areas, dry, moderately well-drained areas (moist grassy and turfy places, often on snowbeds by the edge of melting snowbanks (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, Ellesmere, Parry islands (Eglington, Ellef Ringnes), Cornwallis, Banks, Victoria, King William, Southampton, Coats (Digges).
Northern hemisphere distribution. Circumpolar, or circumboreal (arctic-alpine). 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. Whittemore (1997) noted that R. pygmaeus var. langeana has been described as having deeply divided basal leaves and strongly elongate heads of achenes (at least 5 mm long). These characteristics are not well correlated with one another, however, and the variety does not seem natural.
Illustrations. • Close-up of plant. Plants growing in a run-off slope snow patch, near Ranunculus nivalis. Nunavut, Baffin Island, Ogac Lake. 9 July, 2004. Aiken and LeBlanc 04–031. CAN. • Close-up of flowers. Flowers have 5 yellow petals and 5 sepals. Aiken and LeBlanc 04–031. CAN. • Close-up of plant. Tufted fruiting plant with divided leaves that have petioles of various lengths. Drawing by Mrs. S. Bergh and Mrs. L. Barstad based on a collection Svalbard, Sørkapp Land, Sydcap. September, 1827. B.M. Kkeilhau. With permission of the Botanical Museum University of Oslo, Norway. • Herbarium specimen. Close-up of a flowering plant showing fibrous roots (no rhizomes) and several leaf shapes. Plants collected in the Yukon at Keno Hill, 63°58'N, 135°42'W. 26 July, 1967. R.T. Porsild 962. CAN 313013. • 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..