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

Oxytropis borealis DC.

Fabaceae (Leguminosae), Pea family.

Published in Prodromus 2: 275. 1825.

Type: "e sinu S. Laurentii in terra Tsuchuktschorum (pays des Tchouktchi) septentrionem versus a fretus Beringii. Legumina divisa a leg. ox. montana. m. Fischer 1825". Holotype: G-DC.

Synonymy. O. leucantha auct., non (Pall.) Bunge. 1874.

Oxytropis uralensis subsucculenta Hooker Fl. Bor-Amer. 1: 146. 1831.

Oxytropis viscida var. subsucculenta (Hooker) Barneby, Proc. Calif. Acad. Ser. 4. 27: 246. 1952.

Oxytropis glutinosa sensu A.E.Porsild and Cody 1980, non A.E.Porsild 1951.

Oxytropis glutinosa A.E. Porsild in Bull. Nat. Mus. Canada, No. 121 (Bot. Southeast. Yukon, etc.) 240. 1951.

Vegetative morphology. Plants 7–10 cm high; perennial herbs; caespitose; glandular viscid (to the point of fresh plants feeling clammy, glands sometimes become less visible in dried plants, but glandular verrucae (warts) on the calyx lobes are always visible). Taproot present. Ground level or underground stems absent. Caudex present (well developed and branching). Aerial stems erect. Aerial stem trichomes spreading, or erect (black and white hairs). Leaves mainly basal; alternate; dying annually and non-persistent (blades), or marcescent (midribs of previous season’s leaves persisting). Stipules present; persisting for 2 or more years (in the marcescent build-up at the base of the plant); 10–15 mm long; 3–3.5 mm wide (each side); sheathing; brown, or white (greyish, or pale brown, strongly adnate to the petiole); hairy; long-silky (particularly at the base); apex acuminate (long and narrow). Petioles 5–25 mm long; hairy; long-silky. Petiole hairs longer than the diameter of the petiole; erect; straight, or curved (slightly); smooth. Leaf blades compound. Blades 15–40 mm long, 5–15 mm wide, veins pinnate or with inconspicuous veins. Blade adaxial surface with sessile glands, glabrous or hairy (sparse and with numerous sub-epidermal glands), hairs pilose (very slightly if present), hairs simple, hairs sparse (when present), hairs white, or translucent. Blade abaxial surface with sessile glands, hairy, hairs pilose or long-silky, hairs moderately dense, hairs white, hairs wavy, hairs appressed or spreading. Blade apices acute. Leaflet arrangement pinnate. Leaflets 15–30; 3–7 mm long; 1–2(–2.5) mm wide; oblong, or ovate; veins inconspicuous.

Reproductive morphology. Flowering stems two or more per plant; without leaves. Flowering stems hairy. Flowering stems villous. Flowering stem hairs simple; longer than the diameter of the flowering stem; white or translucent and black (spreading, erect). Inflorescences spicate (very short pedicels and head-like); dense; 2–2.5 cm long; 25–35 mm wide; not elongating as the fruit matures. Floral scales hairy all over (3–7 mm long and sparsely black hairy). Flowers per inflorescence 5–7 (fragrant when fresh); medium-sized; bilaterally symmetrical (zygomorphic). Sepals conventional; 5; fused; 8–9 mm wide; brown, or black (often black with copious hairs). Calyx tubular; 5-lobed; hairy. Calyx hairs pilose (with spreading hairs); glandular; black. Calyx teeth equal or nearly so; with abundant glandular verrucae; 1.8–2.3 mm long. Petals conventional; both free and fused; 5; pink, or purple, or blue (paler or white towards the base); with contrasting markings (particularly dark veins on the banner petal that act as insect guidelines); unlobed (4 petals), or slightly lobed or undulating (banner petal); 15–20(–25) mm long. Corolla papilionaceous; keel with a pointed tip; helmet without 2 small teeth at the apex. Stamens 10. Anther filaments 9 fused into a tube, plus 1 free. Nectaries present. Ovary superior; carpels 1; monomerous. Stigmas per ovary 1. Ovules per ovary 20–30. Fruit sessile, or stalked; with calyx persisting; dry; a legume (beaked at the tip); ovoid, or elongate-cylindrical, or obovate (when dehisced), or oblong; yellowish (or grey); 8–14 mm long; 5–7 mm wide; hairy, or glabrescent (with dark hairs); not distinctly flattened; dehiscent (opening at the apex). Legume unilocular; valves straight. Styles persisting but not modified. Seeds 3–10; 1.8–2.2 mm long (i.e., the longest dimension); brown; surfaces smooth.

Chromosome information. 2n = 16, or 32, or 48.

2n (6x) = 48. Holmen (1962, Alaska); Johnson and Packer (1968, northwestern Alaska, 2n = about 48, as 'glutinosa'); Dawe and Murray (1981, Alaska, two counts); Zhukova and Petrovsky (1983b, eastern Chukotka, two counts).

Ploidy levels recorded 2x/4x.

Taxon as an environmental indicator. The northernmost record is on Banks Island at 73°50'N.

Ecology and habitat. Substrates: hummocks, tundra; dry; calcareous. Gravelly and sandy places, on peat in snow patches.

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, continental Nunavut. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic. Arctic islands: Banks.

Northern hemisphere distribution. Amphi-Beringian, or Cordilleran. South Chukotka, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada.

General notes. Elven et al. (2003) treat Oxytropis borealis as O. glutinosa A.E. Porsild and noted the pattern in North America might justify four regional races: 'borealis' as amphi-Beringian and Alaskan, 'glutinosa' as northwestern Canadian, 'viscida' as Cordilleran, and 'hudsonica' as central-northeastern Canadian ('Hudsonian'). An alternative would be to merge 'borealis' and 'glutinosa' within one subspecies. Because the combinations for subspecies of these taxa are not yet available, here we use the species names O. borealis for the western taxon (as this will be the name published in Flora of North America) and O. hudsonica for this taxon of the Hudsonian region, until a classification is clarified which satisfies the circumpolar morphological discontinuities, available chromosome evidence, and any future molecular evidence.

Welsh (1990) considered that O. borealis in North America consists of an intergrading series of varieties. This whole species complex has fragrant viscid herbage, and was treated as O. viscida by Barneby (1952), but O. borealis is the earliest name in North America (Welsh 1990). In the Canadian Arctic Islands, plants are generally recognisable as belonging to two varieties.

Specimens from Banks Island most closely resemble O. borealis. These plants have calyx teeth that are 2 mm or longer, and possess copious glandular verrucae; the calyces are copiously black hairy. In dried specimens the glands can become less noticeable, but the glandular verrucae on the calyx lobes remain prominent (Barneby 1952, p 239). However, some of the Banks Island specimens approach the more southern var. viscida in that although the leaves generally have 25 leaflets or fewer, some specimens have more leaflets. The distinction between var. borealis and var. viscida is sometimes not possible (Barneby 1952), especially when the plant is in flower, but Barneby gives arguments for recognising the more northern ones as var. borealis. Banks Island specimens have been identified by S.L. Welsh (in 1998), but the distinction between these two varieties requires further study (S.L. Welsh, personal communication, 1999).

The taxon recognised by Porsild's (1957) as O. glutinosa was synonymised under O. borealis var. viscida, but as Welsh (1990) stated," var. borealis consists, at least in part, of what has passed under the name of O. glutinosa Porsild".

Illustrations. • Habitat. Plant growing in Dryas mat with Salix arctica nearby. Banks Island, Aulavik National Park, beside the Thomsen River. 9 July, 1999. Aiken 99–034. CAN. Scale bar in cm. • Inflorescences. Plant with several inflorescences growing erect. N.W.T., Banks Island, Aulavik National Park, beside the Thomsen River. 9 July, 1999. Aiken 99–034. CAN. • Close-up of inflorescence. Inflorescence beginning to flower, a characteristic of O. borealis. N.W.T., Banks Island, Aulavik National Park, beside the Thomsen River. 9 July, 1999. Aiken 99–034. CAN. • Close-up of plant. Herbarium specimen with purple flowers, long tap root, and branching caudex. N.W.T., Banks Island, confluence of the Muskox and Thomsen rivers. 20 July, 1989. C. Mulder. CAN 549806. • Close-up of inflorescence. Close-up showing purple flowers and hairy calyx. Upper right flower shows pointed tip on keel, characteristic of Oxytropis. N.W.T., Banks Island, confluence of the Muskox and Thomsen rivers. 20 July, 1989. C. Mulder. CAN 549806. • Close-up of leaves. The upper surfaces of young leaflets are glabrous and covered with glands. The lower surfaces are covered with long silky hairs. The leaf midrib and the adjacent flowering stem have hairs that are often longer than the petiole is wide. • Side view of stipule. One side of an ovate membranous pale brown stipule with a dark and long acuminate tip. The tip of the other side of the stipule is visible. The base of the stipule has a fringe of long silky hairs. N.W.T., Banks Island. CAN 128014. • Side view of inflorescence. Side view of inflorescence showing the length of the calyx teeth (more than 2 mm long) as a proportion of the total calyx length. In this variety, they are proportionally much longer than those in O. hudsonica. Note the relatively long, green stipule-like floral bracts. N.W.T., Banks Island. CAN 128014. • Close-up of calyx teeth. The two calyx teeth nearest the left have the most conspicuous yellowish glands (one indicated by the white arrow), which is characteristic of the taxa in this legume section (in the Canadian arctic including this species and O. hudsonica). N.W.T., Banks Island, Sachs Harbour. CAN 431898. • 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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