Linum lewisii Pursh
Flax.
Linaceae, flax family.
Fl. Amer. Sept. 1: 210. 1814.
Type: USA: valleys of the Rocky Mts., 19.07.1806, leg. M.Lewis (PH) holotype
Linum perenne L. subsp. lewisii (Pursh) Hultén, Lunds Univ. Årsskr., n. f., avd. 2, 43, 1: 1122. 1947
Vegetative morphology. Plants perennial herbs; 10–30(–60) cm high; glabrous with several densely leafy stems arising close together from a somewhat woody base. Taproot present. Aerial stems erect; glabrous. Leaves distributed along the stems; alternate; simple. Petioles present. 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. Blades linear. Blades adaxial surface glabrous. Blades abaxial surface glabrous. Leaf apices acute.
Reproductive morphology. Flowering stems present. Flowers in inflorescences. Inflorescence racemose (leafy and often one sided); 2–6 cm long (often longer in collections from southern Canada). Flowers per inflorescence 2–6(–10) (flowers; in our region on condensed racemose inflorescences); medium-sized, 5–15 mm in diameter or length. Perianth present. Calyx sepals 5; free. Calyx green (with a conspicuous or narrow transparent margin); glabrous. Petals free; longer than the calyx; 5; blue (or rarely white, fading to pale yellow); 5–9 mm long. Stamens 13. Gynoecia superior. Carpels syncarpous; 5. Styles 5; free (except at the base). Placentation axile. Ovules 2 (per locule). Fruit with calyx persisting; dry (splitting into segments like an orange); a capsule; ovoid; dehiscent. Fruit 4–5 mm long; 4–5 mm wide; brown (where seeds touch the wall, elsewhere green). Seeds 10 (with two large seeds per locule); 2.5–3.5 mm long; brown; with surfaces smooth.
Chromosome information. 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 (1979 Alaska). Ploidy levels recorded 2x.
Distribution. Northern hemisphere distribution: North American; Canada, United States. Low arctic. Range in the Canadian Arctic Archipelago limited. Rare. Arctic Islands: Victoria (two records).
Ecology and habitat. Substrates: slopes; dry; calcareous; rocks, gravel.
Economic uses. Linum lewisii is in the same family 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.
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).
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. A.E. Porsild, 17417, 2–3 Aug. 1949. CAN. • Close-up of inflorecence. Branching racemose inflorescence of blue flowers with five free petals. Note small linear leaves. Garden plant. Ottawa, Canada. • Close-up of flowers. Flowers with five cone-shaped anthers that are shedding pollen and five small spherical stigmas. Cultivated plant. Ottawa. Canada. • Close-up of flower at anthesis. Flower approximately 2 cm in diameter with five free petals that are predominentaly blue, but yellow at the base and five stemens with anthers about to shed pollen. Garden plants. Ottawa. Canada. • Close-up of flower post-anthesis. Flower with anthers shedding pollen and small cone-shaped stigmas becoming receptive. Cultivated plant. Ottawa. Canada. • Inflorescence in fruit.. Racemose inflorescence with capsules borne on long pedicels. Cultivated plant. No voucher. Aiken, 2002. • Close-up of capsule. Capsule that has split open and released seeds. Aiken. 2002. No voucher. • Close-ip of capsule. Capsule that has split open and released seeds. Aiken. 2002. No voucher. • Arctic Island Distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
