Flora of the Canadian Arctic Archipelago

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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

Salix pulchra Cham.

English: Diamond-leaf willow.

Salicaceae, Willow family.

Published in Linnaea 6: 543. 1831.

Type: Alaska, St. Lawrence Island., Cape Espenberg. Holotype: LE

Synonymy. S. planifolia Pursh subsp. pulchra (Cham.) Argus, Can. J. Bot. 47: 798. 1969.

Salix phylicifolia L. subsp. pulchra (Cham.) Hultén, Kungl. Svenska Vetenskapsakad. Handl. 13: 136. 1971.

Salix phylicifolia L. var. subglauca (Andersson) B. Boivin, Naturaliste Canad. 93: 437. 1966.

Salix phylicoides Andersson Oefvers. Vet. Acad. Foerhandl. 15: 123. 1858.

Salix pulchra Cham. var. looffiae C. R. Ball, Madroño 6: 228. 1942

Salix pulchra Cham. var. palmeri C. R. Ball, Madroño 6 :229. 1942.

Salix pulchra Cham. var. yukonensis C. K. Schneider J. Arnold Arb. 1: 72. 1919.

Salix planifolia Pursh var. yukonensis (C. K. Schneider) Argus, Can. J. Bot. 47: 800. 1969.

Vegetative morphology. Plants 10–30(–450) cm high; shrubs; low shrubs, or mid shrubs, or tall shrubs; not colonial. Aerial stems erect, or decumbent. Branches yellow-brown, or red-brown, or brownish; not glaucous (rarely glaucous); glabrous, or hairy, or glabrescent; hairs villous (in patches). Branchlets yellow-green, or brownish; not glaucous (rarely glaucous); glabrous, or hairy; villous, or puberulent. Branchlet hairs sparse, or moderately dense, or very dense; spreading. Buds arctica-type, or caprea-type. Leaves present; distributed along the stems; alternate; dying annually and non-persistent, or marcescent. Stipules present; on first leaves foliaceous; on leaves formed later in the season foliaceous; persisting for 2 or more years, or deciduous in autumn; green; apex acuminate. Petioles 2.8–10(–15) mm long; convex to flat in cross section; glabrous, or hairy; puberulent (sparse). Juvenile leaves yellowish green; glabrous, or hairy; abaxial surfaces pubescent; abaxial hairs sparse; abaxial hairs white (or white and rust-coloured). Leaf blade bases cuneate. Blades 22–75 mm long, length-width ratio 1.7–4.7, 8–26 mm wide, elliptic (to narrowly elliptic) or obovate. Blade adaxial surface shiny or highly glossy, glabrous. Blade abaxial surface glaucous, glabrous (midrib with white and rust-coloured hairs). Blade margins slightly revolute or flat. Blade margins entire and glandular-dotted or serrulate or crenate, with teeth all around the blade or toward the base, with teeth per cm 2–5 (3); apices acuminate, or acute, or obtuse.

Reproductive morphology. Plants dioecious. Inflorescences catkins. Pedicels absent. Catkins flowering before leaves emerge. Male catkins 21–53 mm long; 12–19 mm wide; stout, or sub-globose; peduncles 1.5–5(–7) mm long; sessile, or borne on a flowering branchlet; flowering branchlets 0–3 mm long. Female catkins 40–54 mm long; 8–20 mm wide; slender, or stout; peduncles 2.5–8(–12) mm long; sessile, or borne on a flowering branchlet; flowering branchlets 0–8 mm long. Floral bracts brown, or black; 1.6–2.8 mm long; hairy mainly at apex; hairs moderately dense; hairs straight; apices acute, or rounded; apices entire. Flowers unisexual. Sepals absent. Petals absent. Stamens 2; stamen filaments glabrous. Anthers purple becoming yellow; ellipsoid, or short-cylindrical; 0.4–0.8 mm long. Male flowers abaxial nectaries absent. Male flowers adaxial nectaries narrowly oblong, or oblong; 0.6–1 mm long. Female flowers abaxial nectaries absent. Female flowers adaxial nectaries narrowly oblong, or oblong; 0.4–1.6 mm long (2–3 times longer than the stipe); longer than stipes. Ovary carpels 2. Stipes 0.2–0.8 mm long. Ovaries pear-shaped; slightly bulged below style; hairy; long-silky. Ovary hairs moderately dense, or sparse; white, or white and rust-coloured; appressed; straight; flattened. Styles 1–1.8 mm long. Stigma lobes 0.44–0.63–0.96 mm long. Ovules per ovary 12–16. Fruit a capsule; 3.2–5.6 mm long; hairy.

Chromosome information. 2n = 76.

2n (4x) = 76. Zhukova (1967, 1968, 1969, northeastern Asia); Johnson and Packer (1968, northwestern Alaska); Suda and Argus (1969, Alaska); Zhukova and Petrovsky (1987a, northeastern Asia); Zhukova et al. (1977, northeastern Asia); Petrovsky and Zhukova (1983a, 1983b, northeastern Asia).

Ploidy levels recorded 4x.

Indigenous knowledge. Anderson (1939) noted that this species was used as food in Alaska. The young shoots and catkins were used fresh and also stored in oil for winter use. The bark would be peeled off and the cambium scraped off and eaten.

Ecology and habitat. In the Canadian Arctic Archipelago this rare shrub forms low thickets along river, lake, and streams.

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, continental Nunavut. Arctic islands: Banks.

Northern hemisphere distribution. Amphi-Beringian, or Siberian. Polar Ural – Novaya Zemlya, Yamal–Gydan, Taimyr – Severnaya Zemlya, Anabar–Olenyok, Kharaulakh, Yana–Kolyma, West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada.

General notes. Salix pulchra is a shrubby species with prominent, persistent, linear stipules. The catkins are essentially sessile, the ovaries are glabrous, and the nectaries 2–3 times as long as the stipes.

It is closely related to S. planifolia, which differs from it in having smaller, usually ovate or short-linear, non-persistent stipules. It is sometimes difficult to separate from S. richardsonii based on vegetative material. The two overlap on Banks Island, but they are easily separated by the silky ovaries of Salix pulchra and the glabrous ovaries of S. richardsonii.

This species has been treated as S. planifolia subsp. pulchra (Argus 1973). Subspecies rank was proposed because the two taxa appeared to intergrade where their ranges overlap in the Mackenzie Mountains and in northwestern British Columbia. The intergradation, however, does not seem to extend beyond the overlapping populations. This situation is very similar to that found in S. lanata - S. richardsonii - S. calcicola, and S. brachycarpa - S. niphoclada. Trinomial nomenclature, in all of these cases, was used to show the close evolutionary relationship between these taxa. But inasmuch as such nomenclature is cumbersome to use and is therefore often ignored by the non-taxonomist, its information value is minimal. In addition, since the evidence for intergradation is often indistinct, it appears more appropriate to use binomial nomenclature.

This species, along with S. alaxensis and S. richardsonii, are the tallest growing willows in the Arctic Archipelago. In the Masik River valley, southwestern Banks Island, it forms a dominant shrub tundra in association with S. alaxensis and S. richardsonii (Kuc 1970, 1974).

Illustrations. • Line drawing. a. Male catkins are sessile on the branch. b. Male flowers have 2 stamens, a floral bract with long straight hairs, and a single nectary. c. Female catkins are sessile on the branch. d. Female flowers have a villous ovary with a long style, a long hairy floral bract, and a single floral nectary that is longer than the stipe. e. Leaves are typically oblanceolate and have linear, leaf-like stipules. Coville 1901. • 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.

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