Flora of the Canadian Arctic Archipelago
English: Mackenzie's sweet-vetch,
French: Sainfoin de Mackenzie.
Fabaceae (Leguminosae), Pea family.
Published in Great Basin Naturalist 28: 152. 1968.
Type: Canada, Barren grounds, Point Lake to the Arctic sea, Richardson s.n. Holotype: BM. Isotype: NY.
Synonymy. Hedysarum americanum var. mackenziei (Richardson) Britton, Mem. Torrey Bot. Club 5: 202. 1894.
Hedysarum boreale subsp. mackenziei (Richardson) Á. Löve and D. Löve, Taxon 31: 347. 1982, nom. illeg.
Hedysarum boreale Nutt., Gen. N. Amer. Pl. 2: 110. 1818. Described from USA: North Dakota.
Hedysarium mackenzii Richardson, Bot. App. 745. 1823.
Hedysarum mackenziei var. pabulare (A. Nelson) Polunin, Bull. Natl. Mus. Canada 94 (Biol. Ser. 24): 295. 1940.
Vegetative morphology. Plants 15–40 cm high; perennial herbs; not caespitose. Taproot present. Roots are thick and fibrous. Ground level or underground stems vertical. Caudex present (much branched and sub-ligneous). Aerial stems erect, or ascending. Leaves distributed along the stems; alternate (rarely), or opposite; dying annually and non-persistent. Stipules present; persisting for 2 or more years; (2–)4–8.5 mm long; (1–)2–3 mm wide; sheathing (at the base, for most to the length); brown (or inconspicuously grey); glabrous (over much of the surface), or hairy (at the base, on the margins and at the apex); pilose, or villous; apex acuminate. Petioles 5–25 mm long; hairy (sparsely); strigose. Petiole hairs shorter than the diameter of the petiole; appressed; straight; smooth. Leaf blades compound. Blades 20–80 mm long, (10–)20–30 mm wide, spreading, veins pinnate. Blade adaxial surface dull (silvery grey), hairy (with fine, silvery grey hairs), hairs short-silky or strigose, hairs simple, hairs dense, hairs white, or translucent. Blade abaxial surface hairy, hairs strigose, hairs very dense, hairs white, hairs straight, hairs appressed. Blade apices acute, or rounded. Leaflet arrangement pinnate. Leaflets 5–11(–13); (5–)10–15 mm long; 5–8 mm wide; oblong, or ovate, or lanceolate; veins inconspicuous.
Reproductive morphology. Flowering stems about as high as the leaves, or conspicuously taller than the leaves; without leaves. Flowering stems hairy. Flowering stems strigose (sparse). Flowering stem hairs simple; white or translucent. Inflorescences racemose; 2–8 cm long. Pedicels present, or absent (very short). Bisexual spike(s) with empty bracts at the base (stipule-like). Flowers per inflorescence 5–15; large (showy and sweet scented); bilaterally symmetrical (zygomorphic). Sepals conventional; 5; fused; 6–6.5 mm wide; brown, or black (on the narrow tips). Calyx linear; tubular; 5-lobed; hairy (mostly on inside of lobes and on veins). Calyx hairs strigose; white or translucent. Calyx margins without cilia. Calyx teeth sub-equal or unequal (with narrow, pointed tips, lance- or linear-subulate); 2–2.5 mm long (linear). Petals conventional; both free and fused; 5; purple; with contrasting markings (colour gradation from deep purple at tips of the petals to pale yellowish at the base); unlobed (four petals), or slightly lobed or undulating (banner petal); 15–25 mm long. Corolla papilionaceous; keel blunt; helmet without 2 small teeth at the apex. Wing auricles free from each other, blunt, shorter than the claw. Stamens 10; stamen filaments all equal in length (almost). Anther filaments 9 fused into a tube, plus 1 free. Anthers yellow; 0.5–0.6 mm long. Nectaries present. Ovary superior; carpels 1; monomerous. Stigmas per ovary 1. Ovules per ovary 3–6. Fruit stalked; with calyx persisting; dry; a loment; elongate-cylindrical; brown (at maturity, with conspicuous transverse veins); 30–40 mm long; 6–8 mm wide; hairy (with fine hairs visible at 10×, and conspicuous transverse veins), or glabrous (appearing so to the naked eye); distinctly flattened; indehiscent (but splitting between the articles of the loment). Loment margins wingless. Styles persisting but not modified. Seeds 3–6; 2.5–3 mm long (i.e., the longest dimension); brown; surfaces smooth.
Chromosome information. 2n = 14, 16–17, 28, and 32.
2n (2x, x = 7) = 14. Gillett et al. (1999 onwards, secondary reference).
2n = 16-17 (2x, x = 8). Ledingham (1957, central Canada, 2n = 16 17); Hedberg (1967, northern Canada); Johnson and Packer (1968, northwestern Alaska); Knaben (1968, Alaska, two counts); Mulligan and Cody (1971, 1973, Yukon); Zhukova and Tikhonova (1973, Chukotka); Packer and McPherson (1974, northern Alaska); Yurtsev et al. (1975, eastern Chukotka); Zhukova (1982), Zhukova and Petrovsky (1983b, eastern Chukotka, four plants); Löve and Löve (1982a, central Canada).
2n (4x, x = 7) = 28. Gillett et al. (1999 onwards, secondary reference).
2n (4x, x = 8) = 32. Yurtsev et al. (1975, eastern Chukotka); Zhukova (1983, eastern Chukotka, one plant).
The basic chromosome number 2x = 14 is a character of sect. Gamotion [i.e., not of this section]. The secondary references in Gillett et al. (1999) are questioned.
Ploidy levels recorded 2x and 4x.
Taxon as an environmental indicator. This taxon reaches as far north as Eglinton Island, 75°48'N, where it survives on sunny, warm slopes.
Ecology and habitat. Substrates: tundra, slopes; dry; gravel, clay. Rather dry and gravelly flats, often predominating in dwarf forms.
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec. Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic islands: Parry islands (Eglinton), Banks, Victoria.
Northern hemisphere distribution. North American. East Chukotka, West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Bay.
General notes. Porsild (1964) indicated that plants grow 10–25 cm tall. Plants 40 cm tall have been collected from southern Banks Island, Nelson Head, 2 mi. northeast, 2 July 1952, T. H. Manning and A. Macpherson 77. CAN 220125.
Illustrations. • Habitat. Plants growing in a disturbed, gravel roadside habitat, 30–50 cm high, have pink-purple coloured flowers, Manitoba, Churchill. Aiken and Brysting 01–008. CAN. • Habitat. Plants growing on sand dunes. N.W.T., Banks Island, Sachs Harbour. 28 July, 1981. J.M. Gillett 18901. CAN. • Close-up of plant. Plants growing on sand dunes. N.W.T., Banks Island, Sachs Harbour. 28 July, 1981. J.M. Gillett 18901. CAN. • Close-up of inflorescence. Inflorescence of previous plant. N.W.T., Banks Island, Sachs Harbour. 28 July, 1981. J.M. Gillett 18901. CAN. • Close-up of flower. Close-up of flower with lobed banner petal at the top, two standard petals at the side and two petals fused into a keel at the bottom. Banks Island, Sachs Harbour. 28 July, 1981. J.M. Gillett 18901. CAN. • Close-up of current year's stipule. Relatively inconspicuous membranous brown stipules at the base of a current season's leaf, that are not connate at the base. N.W.T., Banks Island. CAN 220052. • Close-up of persistent stipule. Relatively inconspicuous membranous brown stipules that are not connate at the base. N.W.T., Banks Island CAN 220052. • Close-up of inflorescence. Inflorescence capitate in bud. Note white strigose hairs on the flowering head stem and the blue-purple petals. Sepals are pale brown, membranous at the base and have dark deltoid calyx teeth. N.W.T., Banks Island. CAN 220052. • Plant in fruit. Fruits loments in various stages of development. Loment is a pod constricted between the seeds, and breaking into one-seeded portions. Manitoba, Churchill. Aiken and Brysting 01–008. CAN. • Plant in fruit. A loment showing the constrictions where the pod will break into one-seeded segments. Note remains of petals near the point of attachment to the plant and the remains of a stigma at the opposite end. Manitoba, Churchill. Aiken and Brysting 01–008. CAN. • 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..