Flora of the Canadian Arctic Archipelago
Ranunculaceae, Buttercup family.
Published in Chloris Melvill. 6. 1823.
Type: Described from Canada: Melville Island.
Synonymy. Batrichium subrigidum (W.B.Drew) Ritchie, Can. J. Bot. 34: 300. 1956.
?Ranunculus aquatilis L. var. subrigidus (W.B. Drew) Breitung, Amer. Midl. Naturalist 58: 32. 1957.
Vegetative morphology. Plants 1.5–12 cm high; perennial herbs; caespitose. Only fibrous roots present. Roots wiry, less than 0.3–0.8 mm in diameter. Ground level or underground stems absent. Caudex present (non-fibrous). Aerial stems erect, or decumbent. Leaves heterophyllous (basal leaves fan-shaped to kidney-shaped in outline, shallowly 3–5 lobed; flowering stem leaves deeply 3-cleft); mainly basal; alternate; persistent (basal leaves), or dying annually and non-persistent. Petioles 26–32 mm long. Leaf blade bases obtuse. Blades (9–)15–22(–30) mm long, (8–)14–20(–35) mm wide, obovate (broadly), flat, veins palmate. Blade adaxial surface glabrous. Blade abaxial surface hairy, hairs villous. Blades lobed (3-lobed, with or without 2 lateral lobes again 2-lobed). Blade margins entire. Hydathodes present but inconspicuous. Blade apices obtuse, or rounded.
Reproductive morphology. Plants bisexual. Flowering stems solitary; with leaves. Flowers solitary, or in inflorescences. Inflorescences cymose. Flowers per inflorescence 1–3; medium-sized. Sepals conventional; 5; free; 2–3 mm long; 4.5–6 mm wide; yellow and purple; scarious. Calyx hairy (grey villous, hairs colourless). Calyx hairs white or translucent. Petals conventional; free; 5; yellow; obovate; unlobed; 4.5–6 mm long; 2–3 mm wide. Stamens 30; stamen filaments glabrous. Nectaries present (nectary scale forming a pocket; glabrous). Receptacle 1–8 mm high (1–2 mm in flower, 5–8 mm in fruit; sparsely long-pilose). Ovary carpels 50–60; apocarpous. Stigmas per ovary 1. Placentation parietal. Ovules per ovary 1. Fruit stalk 4–7 mm long; dry; an aggregate of achenes; elongate-cylindrical, or obovate; purple; 6–9 mm long; 3.5–4.5 mm wide (achenes 1.3–1.7 × 0.8–1.2 mm, glabrous, beak lance-subulate, straight or curved, 0.4–0.6 mm); hairy; indehiscent. Styles remaining straight (or somewhat curved).
Chromosome information. 2n = 32.
2n (4x) = 32. Mosquin and Hayley (1966, northern Canada); Zhukova and Tikhonova (1971, Chukotka).
Whittemore (1997), Flora of North America, Vol. 3, gave the chromosome number as octoploid (2n = 64). This is probably based on Mosquin and Hayley (1966, northern Canada, reported as 2n = 64 by Bolkhovskikh et al. 1969) and needs confirmation by voucher specimen before inclusion. Löve and Löve (1975) entered this count as 2n = 32.
Ploidy levels recorded 4x.
Ecology and habitat. Substrates: snow patches, marshes (along the margins), slopes; imperfectly drained moist areas. Moist gravelly or turfy places (Porsild 1957).
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago widespread. Common. Arctic. Arctic islands: Baffin, Ellesmere, Axel Heiberg, Parry islands (Amund Ringnes, Bathurst, Eglington, Ellef Ringnes, Emerald, Loughead, Meighen, Melville, Prince Patrick), Banks, Victoria, Prince of Wales, King William (Melville Peninsula).
Northern hemisphere distribution. Circumpolar (interruptedly high-arctic with European gap). Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, West Chukotka, West Alaska (?), North Alaska Yukon, Central Canada, Ellesmere Land Peary Land.
General notes. Hultén (1971) considered this taxon to be a hybrid of R. nivalis × R. pygmaeus. Elven et al. (2003, 2005) consider it is a good species which occurs within the range of R. pygmaeus and sometimes in company with it, but it is well separated morphologically, with different chromosome ploidy, and partly also ecologically.
Illustrations. • Habit: Banks Island. Flowering plants growing on the sandy margin of the river. N.W.T., Banks Island, Sachs River. 28 July, 1981. J.M. Gillett 18918. CAN. • Herbarium specimen. Flowering plant with variable leaf shapes and rhizomes. Note plant is not tufted. Nunavut, Baffin Island, Kangerdluak. 21 July, 1967. P.J. Weber 1230. CAN 312059. • 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..