Flora of the Canadian Arctic Archipelago
English: Sulphur yellow buttercup,
French: Renoncule soufrée.
Ranunculaceae, Buttercup family.
Published in C.J. Phipps, Voy. North Pole 202. 1774.
Type: Svalbard: Smeerenburg, leg. Phipps, selected by Nilsson, Nord. J. Bot. 16: 7. 1996. Lectotype: BM.
Synonymy. Ranunculus altaicus Laxm. [Nov. Comm. Acad. Petrop. 18: 533. 1774.] subsp. sulphureus (Sol.) Jelen. and Derv.-Sok., Novosti Sist. Vyssh. Rast. 30: 49. 1996.
Vegetative morphology. Plants (3–)5–20 cm high; perennial herbs; caespitose. Only fibrous roots present. Roots slender and numerous on caudex. Ground level or underground stems vertical, or absent; elongate, or compact; 1–2 mm wide (freely rooting at the nodes). Caudex present (short, non-fibrous). Aerial stems erect. Aerial stem trichomes spreading, or erect (and wavy). Leaves heterophyllous (basal leaves palmate with shallow, crenate lobing on the margins; leaves on the flowering stems digitate and deeply divided); mainly basal; alternate; persistent (basal leaves), or dying annually and non-persistent. Petioles 10–90 mm long. Leaf blades simple. Leaf blade bases truncate, or obtuse. Leaves not grass-like. Blades 7–30 mm long, 9–30 mm wide, elliptic or triangular (broadly), flat, veins palmate. Blade adaxial surface hairy, hairs villous, hairs simple, hairs sparse. Blade abaxial surface hairy, hairs villous, hairs sparse, hairs white. Blades lobed or not lobed (basal leaf blades rarely unlobed, usually shallowly 3-lobed,with crenate lateral lobes). Blade margins crenate, with teeth toward the base. Hydathodes present but inconspicuous. Blade apices obtuse, or rounded.
Reproductive morphology. Flowering stems solitary; with leaves. Flowers solitary, or in inflorescences. Inflorescences cymose. Flowers per inflorescence 1–3; large. Sepals conventional; 5; free; 8–13 mm wide; yellow and brown; scarious; non-accrescent. Calyx hairy. Calyx hairs brown. Petals conventional; free; 5; yellow; obovate; unlobed; 6–15 mm long; 5–12 mm wide. Stamens 20–30; stamen filaments glabrous. Nectaries present (nectary scale forming a pocket with margins prolonged beyond the pocket; glabrous). Receptacle 2–5 mm high (2 mm in flower, 5 mm in fruit. This species is characterised by having rusty brown hairs on the receptacle; note that R. nivalis is glabrous but often has a few hairs on the apex of the receptacle); surface hairy (brown hispid). Ovary carpels 60–75; apocarpous. Stigmas per ovary 1. Placentation parietal. Ovules per ovary 1. Fruit dry; an aggregate of achenes; obovate, or elongate-cylindrical; yellowish; 1–12 mm long; 6–10 mm wide (achene 1.5–2.5 × 1.4–1.8 mm, glabrous or sparsely brown-hispid; beak slend, straight or curved, 0.8–1.4 mm long); indehiscent. Styles remaining straight. Seeds 1.
Chromosome information. 2n = 42, 56, 64, 80, 96–98.
2n = 42. Mosquin and Hayley (1966, northern Canada); Scott (1974a);
2n (7x) = about 56. Böcher (1938b, Greenland?);
2n (8x) = 64. Krogulevich (1976a and b, 1978, southern and northern Siberia); Lavrenko and Serditov (1986, northern Russia); Lavrenko et al. (1989, northern Russia);
2n = 76. Sokolovskaya (1963, northeastern Asia, Kamtch);
2n (10x) = 80. Flovik (1936, 2n = about 80); Mosquin and Hayley (1966, northern Canada, 2n = about 80); Zhukova (1980, southern Chukotka); Malakha (1990, northeastern Asia);
2n = about 84. Mosquin and Hayley (1966, northern Canada); Zhukova et al. (1973, northeastern Asia);
2n (12x) = 96 to about 98. Langlet (1936); Flovik (1940, Svalbard); Nygren in Löve and Löve (1948, northern Europe); Jørgensen et al. (1958, Greenland); Sokolovskaya (1958, 1962); Sokolovskaya and Strelkova (1960, 1962); Mosquin and Hayley (1966, northern Canada, 2n = about 98); Knaben and Engelskjøn (1967, northern Norway); Sokolovskaya (1968, northeastern Asia Koryak), Packer and McPherson (1974, northern Alaska); Göpfert (1974); Krogulevich in Malyshev (1976b, northern Siberia); Zhukova and Petrovsky (1976, western Chukotka); Petrovsky and Zhukova (1981, Wrangel Island); Zhukova (1982, northeastern Asia).
Löve and Löve (1975) reported only the chromosome number 2n = 96 for this species.
Ploidy levels recorded 8x/10x/12x.
Ecology and habitat. Substrates: wet meadows, snow patches. Ranunculus sulphureus is usually caliphilous, while R. nivalis is almost always a calcifuge and usually found on slightly drier and often much more humic sites. Ranunculus sulphurus is much more typical of snow banks. When these species are found growing together, R. nivalis blooms earlier and is well into fruit before R. sulphureus begins to flower (Elven, personal communication, 2005). Growing in wet moss by brooks and in herbmats, often near the edge of a melting snowbank (Porsild 1957).
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec. Range in the Canadian Arctic Archipelago widespread. Common. Arctic. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands (Bathurst, Eglington, Meighen, Melville, Prince Patrick), Cornwallis, Banks, Victoria, Prince of Wales, Somerset, King William, Southampton, Coats (Melville Peninsula).
Northern hemisphere distribution. Circumpolar. Northern Fennoscandian, 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. The name R. altaicus has sometimes been applied for the arctic plants. However, true R. altaicus seems to be a diploid (2n = 16, Krasnikov and Schaulo 1986, Siberia).
Illustrations. • Habitat. Plants with yellow flowers in moss mat. Norway, Svalbard, Fjordnibba. 5 August, 1987. Photograph by R. Elven. • Close-up of plant. Note the brown hairy 'sepals'. Norway, Svalbard, Sabine Land, Noisdalen Valley. 6 August, 1987. Photograph by R. Elven. Voucher at 0. • Herbarium specimen. Note roots much longer than the plant is tall, lobed leaves and a flower that has dried pinkish. Nunavut, Ellef Ringnes Island. 14 July, 1954. S.D. MacDonald 220. CAN 233803. • Close-up of pressed bud. Plant with one fully open flower and a flower bud with the calyx visible. Note the dense dark brown hairs on the calyx surface. S.D. MacDonald 220. CAN 233803. • Close-up of plant. Note 'fan-like' lower leaves, i.e. spread out on the same plane. Brown hairs visible on sepals. Norway, Svalbard, Kapp Thordsen. July, 1997. Photograph by R. Elven. • Infrutescences. Fruiting heads of apocarpous ovaries forming an aggregate of achenes. Note the withered sepals (brown-haired) still hanging on. This High Arctic species is regularly insect pollinated and has an abundant fruit production. Norway, Svalbard, Kapp Thordsen. August, 1997. Photograph by R. Elven. • 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..