Flora of the Canadian Arctic Archipelago


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

Saxifraga platysepala (Trautv.) Tolm.

English: Spider plant, flagellate saxifrage,

French: Saxifrage des ruisseau,

Inuktitut: Kakillarnaliit.

Saxifragaceae, Saxifrage family.

Published in Bot. Mater. Gerb. Bot. Inst. Komarova Akad. Nauk S.S.S.R. 19: 172. 1959.

Type: "Saxifraga flagellaris. East coast of Greenland, Sabine", 1830, leg. Lindley, selected as lectotype by Webb and Gornall, Man. Saxifrag. 41.1989. Lectotype: K: specimens numbered 1–5.

Synonymy. Saxifraga flagellaris Willd. var. platysepala Trautv., Phaenog. Pfl. Hochnord. 42. 1847.

Saxifraga flagellaris Willd. var. platysepala Trautv. Fl. Taimyr. 41. 1856.

Saxifraga flagellaris Willd. subsp. platysepala (Trautv.) A.E. Porsild, Bot. Tidsskr. 51: 295. 1954.

Saxifraga flagellaris auct., non Willd. 1810.

Vegetative morphology. Plants 1.5–15 cm high; perennial herbs (living for 2–3 years, but dying after flowering); caespitose; sometimes vegetatively proliferating by bulbils on stems or leaves (on the end of stolons). Ground level or underground stems horizontal; stoloniferous (stolons long, filiform, naked, often bright red and terminating in a tiny rosette that attaches to the substrate by adventitious roots); elongate. Caudex present (short). Aerial stems erect. Leaves heterophyllous (basal leaves usually wider with long spine-like bristles; bract leaves below the inflorescence with glandular hairs), or not heterophyllous (leaves similar in shape); basal in a rosette, or distributed along the stems; erect; alternate; persistent and marcescent. Petioles present, or absent; 0–6 mm long. Leaf blades simple. Leaf blade bases truncate. Blades 3–10 mm long, 1–4 mm wide, elliptic or oblanceolate or obovate or spatulate, flat, with inconspicuous veins. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blades lobed. Blade margins entire or glandular-dotted, with glandular hairs (on stiff stalks). Hydathodes present and conspicuous, or absent (small, near the leaf apex on the upper surface; they do not secrete lime). Blade apices acute, or obtuse (rarely).

Reproductive morphology. Flowering stems solitary; with leaves. Flowering stems hairy. Flowering stems pilose. Flowering stem hairs simple; shorter than the diameter of the flowering stem; white or translucent (with dark glandular tips); glandular hairs present. Flowers solitary, or in inflorescences. Inflorescences without bulbils; cymose; 0–1 cm long. Pedicels present; with glandular hairs. Flowers per inflorescence 1–5; medium-sized. Sepals conventional; 5; free; 1.3–2 mm long; 2.5–3 mm wide; green, or purple. Calyx hairy. Calyx hairs glandular; white or translucent. Petals conventional; free; 5; yellow; obovate; unlobed; 6–10(–11.5) mm long; 3–4 mm wide. Stamens 10; stamen filaments glabrous. Anthers yellow; sub-globose; 0.5–0.6 mm long. Nectaries present. Receptacle 0.5–1 mm high. Ovary partly inferior; carpels 2; partly fused. Ovaries glabrous. Placentation axile. Ovules per ovary 50–100 (approx.). Fruit with calyx persisting (along with other remains of the flower); dry; a capsule (rarely collected in the Canadian Arctic); spherical (with two horn-like styles); brown, or purple; (5–)8–12 mm long; 3–6 mm wide; dehiscent; splitting to the base into separate segments. Seeds 50–100 (approx.); 0.9–1.1 mm long; brown; surfaces smooth, ridged (seen at 40×).

Chromosome information. 2n = 32.

(2n)= 32. Flovik (1940, Svalbard); Holmen (1952, Greenland); Wiens and Halleck (1962); Mosquin and Hayley (1966, northern Canada); Hedberg (1967, northern Canada); Zhukova (1968, northeastern Asia); Packer and McPherson (1974, northern Alaska); Zhukova and Petrovsky (1987a, northeastern Asia); Devyatov et al. (1997, northeastern Asia).

Ploidy levels recorded 4x.

Taxon as an environmental indicator. This is a colonising species that is unable to withstand competition and is indicative of damp open plains of clay or gravel. Polunin (1940) reported the northernmost record as Cape Bennet, 83°02'N, on the north coast of Greenland. It has since been collected in Canada on Ward Hunt Island, 83°05'N.

Ecology and habitat. Substrates: rocks (barrens, usually in wet gravel); calcareous. Simmons (1906) claimed that the species is usually biennial, whereas Gelting (1934) indicated that it is usually triennial in east Greenland. When the mother plant dies after flowering, the young rosettes are detached and may blow around on snow during the winter, becoming a means of propagation. Simmons (1906) stated that the fruits hardly ever ripen on Ellesmere, and reproduction and dispersal are mainly by vegetative means. Warming (1909) considered the species protandrous, but also that self-pollination is almost inevitable.

North American distribution. Alaska, Yukon (?), Northwest Territories Islands, Nunavut Islands. Range in the Canadian Arctic Archipelago widespread (adjacent to, and north of the Parry Channel). Common (western High Arctic). High Arctic. Arctic islands: Devon, Ellesmere, Axel Heiberg, Amund Ringnes, Ellef Ringnes, Parry islands (Bathurst, Loughead, Melville), Cornwallis, Banks, Victoria (Steffenson), Prince of Wales, Somerset (Meighen).

Northern hemisphere distribution. Circumpolar. Svalbard – Franz Joseph Land, Polar Ural – Novaya Zemlya, Taimyr – Severnaya Zemlya, Yana–Kolyma, Wrangel Island, West Alaska, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. This species is sometimes recognised as Saxifraga flagellaris subsp. platysepala (Porsild 1964, Porsild and Cody 1980).

Porsild and Cody (1980) recognised:

1. Saxifraga flagellaris subsp. flagellaris: in which the hypanthium is broadly campanulate (bell-shaped) and green. It is of Amphi-Beringian range, and known only from calcareous rocks along the east slopes of the Mackenzie and Richardson Mountains.

2. S. flagellaris subsp. platysepala (Trautv.) Porsild: is a High Arctic and nearly circumpolar taxon. It is mostly 1-flowered, with a turbinate (top-like), rather than campanulate hypanthium with dark purple sepals that are obovate-oblong, united in the lower third, and covered by stalked, purple-headed glands. They indicated that this taxon has not been reported from the continent. Polunin (1940) commented that although the species as a whole is very variable he had not been able to find marked taxa within the Canadian Arctic.

The geographic separation of the subspecies recognised in Porsild and Cody (1980) and the strength of distinct characters are regarded as sufficient to justify recognising the taxon as a distinct species. However, Porsild and Cody's (1980) subsp. flagellaris is Saxifraga setigera Pursh (or S. flagellaris subsp. setigera (Pursh) Tolm.). Willdenow's S. flagellaris s. str. is probably restricted to the Caucasus (Elven, 2005, personal communication).

Galloe (1910), discussing the fleshy leaves of S. flagellaris, suggested there are three features that appear to be useless rudiments inherited from parent plants with foliage leaves similar in structure to those of the present-day S. flagellaris. These are (a) functionless (permanently closed) stomata, (b) functionless hydathodes (in which the water pores are closed), and (c) light-orientated (obliquely placed) palisade cells.

Polunin (1940, p. 264) noted that "this extremely attractive high-arctic and alpine species, was known to the old sailors and whalers as 'spider plant' on account of its round 'body' and long, leg-like 'flagellae' subtending daughter individuals". He reported curious contradictions with regard to substrate pH relationships. Scholander (1934) says that it is "fairly common in North-East Land, (Greenland) except in the pure dolomite areas, where it is almost lacking". Gelting (1934) wrote, "as I have not found the species outside soil rich in lime, I consider it calciphilous". Polunin (1940) stated that he had never found it on soils that were at all highly calcareous either in Spitsbergen or in Arctic America, but always in rather exposed barren situations where the soil was nevertheless lastingly damp, owing to poor drainage or occasionally to feeding from a long-lasting snowdrift. Polunin's observations are true for plants found growing beside the road to "Satellite hill" near Resolute Bay, Cornwallis Island.

Illustrations. • Habitat. 'Spider saxifrage' growing in moist moss with long red stolons spreading in several directions. Nunavut, Cornwallis Island, Resolute Bay. • Habit. 'Spider plant' or 'Flagellate saxifrage' named by sailors in reference to the long red stolons at the base of the plant. Nunavut, Cornwallis Island, Resolute Bay. • Habit. Compact plant with a build-up of dead leaves at the base, conspicuous trichomes on the green leaves, and red stolons. The green sepals have glandular hairs on the margins. Nunavut, Axel Heiberg Island, Mokka Fiord. L. Gillespie 6100. CAN. • Stolons. Stolons (black arrow) ending in rooting rosettes (white arrow). Nunavut, Axel Heiberg Island, Mokka Fiord, meadow just below the top of an escarpment. L. Gillespie 6100. CAN. • Close-up of flower. Flower with sepals that have glandular hairs, 5 yellow petals without markings, 10 anthers some of which are visible, and two red carpels that are topped with yellow disc-shaped stigmas. Drawing from Warming 1909. p.186. • 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.