Flora of the Canadian Arctic Archipelago
English: Limestone willow,
French: Saule calciole,
Inukitut: Uqaujaq (Nunavik).
Salicaceae, Willow family.
Published in Rhodora 13: 251. 1911.
Type: Canada: Nunavut, North Twin Island (incorrectly as South Twin on label), James M. Macoun, Holotype: CAN.
Synonymy. Salix lanata L. subsp. calcicola (Fernald and Wiegand) Hultén, Ark. Bot., ser. 2, 7, 1: 41. 1967.
Salix calcicola Fernald and Wieg. var. nicholsiana Polunin, J. Bot. 76: 98. 1938.
Salix richardsonii Hooker var. macouniana Bebb, Bot. Gaz. 14: 50. 1889.
Vegetative morphology. Plants 9–130 cm high; shrubs; low shrubs; not colonial, or forming colonies by layering. Aerial stems erect, or decumbent. Branches red-brown, or grey-brown, or yellow-brown; weakly glaucous, or not glaucous; glabrous, or hairy, or glabrescent (usually persistent); hairs villous. Branchlets red-brown, or yellow-brown; not glaucous, or weakly glaucous; hairy; villous. Branchlet hairs sparse, or moderately 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 acute, or obtuse, or rounded. Petioles 1.5–2.8–9 mm long; shallowly concave in cross section, or convex to flat in cross section; hairy; villous, or pilose. Juvenile leaves yellowish green, or reddish; hairy; abaxial surfaces villous (abaxial side only); abaxial hairs moderately dense; abaxial hairs white. Leaf blade bases obtuse, or rounded, or cordate. Blades 16–32–61 mm long, length-width ratio 0.7–1.5–2.6, 10–22–44 mm wide, elliptic (or broadly elliptic, to sub-circular). Blade adaxial surface dull, glabrous or hairy or glabrescent, hairs villous or pilose, hairs sparse or moderately dense, hairs white, or translucent. Blade abaxial surface glaucous, glabrous or hairy or glabrescent, hairs pilose or villous, hairs sparse or moderately dense, hairs white, hairs straight, hairs spreading. Blade margins slightly revolute or flat. Blade margins entire and glandular-dotted or serrulate (usually minutely toothed), with teeth all around the blade or toward the base, with teeth per cm 6–18 (11); apices acuminate, or acute, or rounded.
Reproductive morphology. Plants dioecious. Inflorescences catkins. Pedicels absent. Catkins flowering before leaves emerge. Male catkins 18–45 mm long; 13–21 mm wide (sessile); stout; peduncles 0–8 mm long; sessile (or borne on a non-leafy branchlet). Female catkins 22–72 mm long; 12–25 mm wide (sessile); stout; peduncles 0–7 mm long; borne on a flowering branchlet, or sessile; flowering branchlets 0–5 mm long. Floral bracts brown, or black; 1.2–3.2 mm long; hairy all over; hairs moderately dense; hairs straight; apices rounded, or acute; apices entire. Flowers unisexual. Sepals absent. Petals absent. Stamens 2; stamen filaments glabrous. Anthers purple becoming yellow; ellipsoid, or short-cylindrical; 0.5–0.7 mm long. Male flowers abaxial nectaries absent. Male flowers adaxial nectaries narrowly oblong, or oblong; 0.5–1.2 mm long. Female flowers abaxial nectaries absent. Female flowers adaxial nectaries oblong; 0.6–1 mm long; longer than stipes, or equal to stipes (rarely shorter). Ovary carpels 2. Stipes 0.2–1.2 mm long. Ovaries pear-shaped, or inverse club-shaped; gradually tapering to style; glabrous. Styles 1.6–3 mm long (conspicuously long). Stigma lobes 0.2–0.38–0.56 mm long. Ovules per ovary 13–18. Fruit a capsule; 4.4–8 mm long; glabrous.
Chromosome information. 2n = 38.
2n (2x) = 38. Löve and Löve, in Löve (1982a, Churchill, Manitoba).
Ploidy levels recorded 2x.
Ecology and habitat. Forming small thickets, about 0.5 m tall, on calcareous substrate. Usually in wet, stony or gravelly places, rubble above the high tide line, and stream margins; but also on sandy and silty shores of brooks, low dunes, and clay frost boils.
North American distribution. Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Arctic islands: Baffin, King William, Southampton, Coats (Boothia Peninsula).
Northern hemisphere distribution. North American (American Atlantic). Central Canada, Labrador Hudson Bay.
General notes. Salix calcicola is a low, erect shrub. The leaves are usually broad to sub-circular, the margins are usually minutely toothed, the stipules are small and usually ovate, the catkins are sessile, the ovaries are glabrous, and the stipes and styles long.
This species has been treated as S. lanata subsp. calcicola (Hultén 1968). Subspecies rank was proposed because the two taxa were thought to intergrade where their ranges overlap in the eastern Arctic. The intergradation, however, is not clear, and hybridisation between S. calcicola and S. richardsonii is not proved. This situation is very similar to that found in S. lanata - S. richardsonii, S. lanata - 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, the evidence of intergradation is often indistinct or non-existent, suggesting that the use of binomial nomenclature may be more appropriate.
Salix calcicola × S. richardsonii. Polunin described S. richardsonii var. mckeandii (1940) and S. calcicola var. nicholsiana (1938), which he thought were hybridising and intergrading on Baffin and Southampton islands. He claimed to have seen some suggestion of hybridisation between S. calcicola and S. richardsonii on Southampton Island, but no clear evidence of hybridisation elsewhere. This problem requires field study.
Illustrations. • Habitat: Dorset. Willow growing in Carex saxatilis meadow in damp area beside a road. Nunavut, Baffin Island, Cape Dorset. 2 August, 2005. Aiken. No voucher. • Habit:Baffin Island. Plant growing as a low erect shrub in a "sedge" meadow. Nunavut, Baffin Island, Iqaluit. 25 July, 1982. J.M. Gillett 19060. CAN. Photograph by J.M. Gillett. • Habit: Newfoundland. This species is typically prostrate in habit when growing on limestone gravel. Newfoundland. Pointe Riche. 23 June 1969. • Close-up of buds in fall. well-developed buds on the tips of a branch in the fall. Without dissection it is not possible to know whether they will develop into leaves or a catkin the following spring. 2003. Photograph by Carolyn Mallory 2003. No voucher. • Close-up of a female catkins. Female catkins showing flowers with glabrous ovaries and broadly elliptic leaves that are pilose or villous. Nunavut, Baffin Island, Iqaluit. 25 July, 1982. J.M. Gillett 19060. CAN. Photograph by J.M. Gillett. • 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..