Flora of the Canadian Arctic Archipelago
Linaceae, Flax family.
Published in Fl. Amer. Sept. 1: 210. 1814.
Type: USA: valleys of the Rocky Mts., 19.07.1806, leg. M. Lewis. Holotype: PH.
Synonymy. Linum perenne L. subsp. lewisii (Pursh) Hultén, Acta Univ. Lund., n.s., avd. 2, 43, 1: 1122. 1947.
Vegetative morphology. Plants 10–30(–60) cm high; perennial herbs. Taproot present. Ground level or underground stems vertical. Aerial stems developed; erect. Leaves present; distributed along the stems; alternate; dying annually and non-persistent. Petioles absent. Leaf blades simple. Leaf blade bases obtuse. Blades (4–)6–12 mm long (to 25 mm long in specimens from continental North America), 0.5–2.5 mm wide, divaricate, linear, flat, appearing single-veined or with inconspicuous veins. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins glabrous; apices acute.
Reproductive morphology. Flowering stems two or more per plant. Inflorescences racemose (leafy and often one sided); 2–6 cm long (often longer in collections from southern Canada). Flowers per inflorescence 2–6 (in the arctic island specimens on condensed racemose inflorescences, many more flowers per inflorescence futher south); medium-sized. Sepals conventional; 5; free; green (sepals with conspicuous transparent margins). Calyx glabrous. Petals conventional; free; longer than the calyx; 5; blue (or rarely white, fading to pale yellow); with contrasting markings (darker insect guidelines in the petals and a yellow throat); obovate; unlobed; 5–9 mm long. Stamens 5. Anthers reddish, becoming yellow. Ovary superior; carpels 5; syncarpous. Styles 5; free. Placentation axile. Ovules per ovary 10 (2 per locule). Fruit stalked; with calyx persisting; dry (splitting into segments like an orange); a capsule; ovoid; brown; 4–5 mm long; 4–5 mm wide; surface venation ribbed; not distinctly flattened; dehiscent. Seeds 10 (with two large seeds per locule); 2.5–3.5 mm long; brown; surfaces smooth.
Chromosome information. 2n = 18.
2n = 18. Kikuchi (1929); Ray (1944); Taylor and Brockman (1966, western Canada); Harris (1968); Ockendon (1968); Mosquin (1971, northwestern Canada, southern USA, three counts); Löve and Löve (1975); Dawe and Murray, in Löve (1979, Alaska).
Ploidy levels recorded 2x.
Ecology and habitat. Substrates: slopes; dry; rocks, gravel; calcareous.
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, continental Nunavut, northern Quebec (here represented by subsp. lepagei). Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic. Arctic islands: Victoria (two records).
Northern hemisphere distribution. North American. North Alaska Yukon, Central Canada.
Economic uses. Linum lewisii is in the same genus as commercial flax that is used in the production of linen. The seeds of linen flax (L. usitalissimum L.) are pressed to produce linseed oil.
General notes. Mosquin (1971) made a very good case for recognition of two subspecies, one widespread (subsp. lewisii) and one restricted to the Hudson and James Bay shores (subsp. lepagei). The plants collected in the Arctic Archipelago are subsp. lewisii. One collection is from the site of a Rough-legged Hawk (Buteo lagopus) nest, suggesting that it was accidentally introduced to the area by birds.
Kikuchi (1929) reported on the difference of chromosome numbers in Linum species.
Illustrations. • Herbarium specimen. Plants collected from a rocky ledge above the nest of an America rough leg hawk. N.W.T., Victoria Island, Head of Minto Inlet, very scarce. 2–3 August, 1949. A.E. Porsild 17417. CAN. • Close-up of inflorescence. Branching racemose inflorescence of blue flowers with five free petals. Note small linear leaves. Garden plant. Canada, Ottawa. • Close-up of flower at anthesis. Flower approximately 2 cm in diameter with five free petals that are predominentally blue, but yellow at the base and five stamens with anthers about to shed pollen. Garden plants. Canada, Ottawa. • Inflorescence in fruit. Racemose inflorescence with capsules borne on long pedicels. Cultivated plant. Aiken 2002. No voucher. • Close-up of capsule. Capsule that has split open and released seeds. 2002. Aiken. No voucher. • 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..