Flora of the Canadian Arctic Archipelago
Rosaceae, Rose family.
Published in Mém. Acad. Imp. Sci. St. Petétersb. Hist. Acad. 5: 543. 1815.
Type: Described from the Russian Far East, 'Terra Tschuktschorum ad sin. St. Lawrentii', leg. Eschscholtz, Holotype: LE? (see Notes)
Synonymy. Potentilla ledebouriana A.E. Porsild, Bull. Natl. Mus. Canada 121: 226. 1951.
Vegetative morphology. Plants (3–)5–10(–15) cm high; perennial herbs; caespitose. Taproot present. Ground level or underground stems vertical; 5–10 mm wide. Caudex present (short, or rarely a longer, elongated caudex with dark brown to blackish leaf remains). Aerial stems branching from a tap at or near ground level into two or more branches. Leaves mainly basal; alternate; dying annually and non-persistent, or marcescent. Stipules present; (5–)8–10(–15) mm long; 1.5–3 mm wide; not sheathing; green (pinkish when fresh, reddish brown when marcescent); hairy; villous and long-silky; glandular; apex acute. Petioles (3–)5–15(–25) mm long; with sessile glands (mostly hidden by hairs); hairy; villous, or long-silky. Petiole hairs spreading; straight, wavy, and crispate; smooth. Leaf blades compound. Blades (7–)10–15(–25) mm long, 15–25(–30) mm wide, veins palmate (leaflet veins pinnate). Blade adaxial surface with sessile glands, hairy, hairs villous or long-silky, hairs simple, hairs sparse or moderately dense, hairs white, or translucent. Blade abaxial surface dull (when visible), hairy, hairs tomentose (between veins) or long-silky (on veins), hairs very dense, hairs white, hairs straight or wavy, hairs appressed (the tomentose hairs) or spreading (the pilose hairs). Blade margins dentate, with non-glandular hairs, with 2–3(–4) teeth on each side of the blade (rarely), with teeth all around the blade; degree of incision (25–)40–60(–80)%; apices obtuse, or rounded. Leaflet arrangement palmate. Leaflets 3; (7–)10–15(–22) mm long; (6–)8–10(–12) mm wide; obovate; veins conspicuous. Apical leaflet base not distinctly stipitate.
Reproductive morphology. Plants bisexual, or agamospermic (possibly). Flowering stems conspicuously taller than the leaves, or about as high as the leaves (rarely); with leaves. Flowering stems hairy. Flowering stems tomentose and villous (sparsely). Flowering stem hairs simple; shorter than the diameter of the flowering stem, or longer than the diameter of the flowering stem (rarely); white or translucent. Flowers solitary, or in inflorescences (rarely). Inflorescences cymose (if applicable). Pedicels present (if applicable). Flowers per inflorescence 1(–3); medium-sized, or large. Sepals conventional. Epicalyx present. Epicalyx segments (4–)5–6(–7) mm long. Epicalyx segments 1–2 mm wide. Epicalyx segments equal in length to the calyx segments (approximately). Epicalyx segments narrower than the calyx segments, or equal in width to the calyx segments (rarely). Sepals 5; free; 2–3 mm long; 5–7(–8) mm wide; green; accrescent. Calyx with sessile glands; hairy. Calyx hairs pilose, or villous, or long-silky; white or translucent. Calyx margins without cilia. Petals conventional; free; 5; yellow; without contrasting markings; obovate; slightly lobed or undulating; (6–)7–10(–11) mm long; (7–)8–11(–12) mm wide. Stamens 20–30 (numerous); stamen filaments glabrous. Anthers yellow; ellipsoid, or triangular; 0.3–0.5 mm long. Ovary superior; carpels 35–50; apocarpous. Styles 0.6–1 mm long; straight; basal portion covered with short papillae, less than 0.1 mm high. Ovules per ovary 1. Fruit sessile; with calyx persisting; dry; an aggregate of achenes; ovoid; green at maturity, or straw-coloured; 1.4–1.8 mm long; 0.8–1.2 mm wide; glabrous; surface venation reticulate, or appearing veinless; indehiscent.
Chromosome information. 2n = 28, or 42.
2n (2x) = 14. Zhukova and Petrovsky (1985b, north and northeastern Asia); Sokolovskaya et al. (1985, northeastern Asia, as P. vulcanicola);
2n (4x) = 28. Mulligan and Porsild (1969, Yukon; 1970, northwestern Canada); Zhukova and Petrovsky (1971, Wrangel Island; 1972, 1975, western Chukotka); Zhukova et al. (1973, northeastern Asia); Zhukova and Tikhonova (1973, Chukotka); Zhukova (1980, southern Chukotka); Packer and Witkus (in Á. Löve 1982, western Canada); Yurtsev (1984, as P. subvahliana, counted on the holotype); Zhukova and Petrovsky (1985b, northern and northeastern Asia, as P. uniflora, P. subvahliana and as P. vulcanicola);
2n (6x) = 42. Sokolovskaya and Strelkova (1960, as P. uniflora); Petrovsky and Zhukova (1981, Wrangel Island, as P. uniflora subsp. subvillosa); Zhukova and Petrovsky (1985b, north and northeastern Asia). Supposed basic chromosome number of family 7.
Ploidy levels recorded 2x, 4x, and 6x.
Ecology and habitat. Substrates: tundra, slopes (dry gravel hillsides), ridges, cliffs; dry; rocks, gravel, sand; with low organic content; calcareous. Exposed ridges and heaths, more often on open wind-eroded patches than in fully closed vegetation. Probably confined to circumneutral to basic substrates in the Arctic.
North American distribution. A North American - Beringian species not previously recognised for the Arctic islands. The specimens from Banks and Victoria match those from continental North America east of the Mackenzie River and material from the Richardson, and British Mountains. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic, alpine. Arctic islands: Banks, Victoria.
Northern hemisphere distribution. Amphi-Beringian, or Cordilleran. Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska Yukon, Central Canada.
General notes. See also notes for P. vahliana. Several specimens from Banks and Victoria Islands, previously included in P. vahliana, differ from that relatively common taxon by having a pure white indumentum, slightly more deeply dissected leaflets, and most conspicuously by lacking an elongated caudex thickly covered by leaf remains. These specimens were redetermined to P. uniflora, being inseparable morphologically from specimens of P. uniflora collected on continental North America. They have previously been overlooked, both in the islands and on the mainland coast east of the Mackenzie River, and the species distribution may be more widespread in the archipelago than indicated here.
The holotype specimen is recorded from the Russian Far East, 'Terra Tschuktschorum ad sin. St. Lawrentii', leg. Eschscholtz, in LE. Potentilla uniflora in the current meaning has not been observed at Lavrentiya (St. Lawrence Bay) (Yurtsev, personal communication, 2003). The earlier collection which might have been available to Ledebour is Adams' collection from the lower reaches of Lena River and Bykov Mts. in northern Yakutia. These plants look like Ledebour's paratypes.
Illustrations. • Habitat. Plants in boulder field. Alaska, Alaska Range, Mount Healy. July, 1998. Voucher at 0. Photograph by R. Elven. • Close-up of plant. Flowering small tussock. Note leaflets with a few coarse teeth on the margins. Alaska, Alaska Range, Donelly Dome. 12 July, 1998. Voucher at 0. Photograph by H.H. Grundt. • Close-up of plants. Small and compact plants with densely compact leaves, short caudices, and a long underground branching tap-root. Right, the base of a pressed plant showing the reddish brown stipules. Leaf indumentum is white-silky as compared with the yellowish grey indumentum of P. vahliana. N.W.T., Victoria Island, Holman. CAN 485174. • 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..