Luzula wahlenbergii Rupr.
Juncaceae, rush family.
Beitr. Pfl. Russ. Reich. 2: 58. 1845.
Plants caespitose (loosely); with short horizontal stems and slender culms; more than 15 cm high; 15–35 cm high. Ground-level or under-ground stems horizontal (not always present on specimens), or vertical and often branched; compact (when horizontal). Aerial stems erect; circular or oval in cross-section; glabrous. Leaves mostly basal; alternate; marcescent. Petioles absent. Ligules absent. Blades 50–100 mm long; 2.5–6 mm wide; straight; linear; flat, or involute (at the tips); with parallel veins; adaxial surface glabrous. Blades abaxial surface glabrous. Leaf margins with non-glandular hairs (simple, unbranched, glabrescent). Leaf apices acuminate.
Flowering stems with leaves (1–5 cm long); glabrous. Leaf or reduced bract closely associated with the base of the inflorescence present; reduced, or scale-like. Inflorescences paniculate, or cymose (also described as subcymose); inflorescence diffuse; inflorescence 3–8 cm long. Inflorescence primary branches 10–50 mm long; with spreading secondary branches. Flowers per inflorescence 20–50; small, less than 5 mm in diameter or length; sessile or subsessile, or borne on a stalk. Floral bracts apex lacerate. Calyx sepals 3; free; brown; scarious; glabrous. Petals 3; free; brown; lanceolate; unlobed; 1.9–2.1 mm long; same length as the calyx. Stamens 6. Anthers 0.5–0.7 mm long. Carpels syncarpous; 3. Gynoecia superior. Styles completely fused. Styles 1. Stigmas per style 3. Ovules 3. Fruit with calyx persisting; a capsule; ovoid; not distinctly flattened; dehiscent; 2.4–2.6 mm long; 1–1.3 mm wide (intact capsules); sessile; dry; brown. Seeds 3; 1–1.3 mm long; brown; smooth.
Chromosome information. 2n = 24, 36 (Chrtek and Krisa, 1980).
Distribution. Circumpolar. Low arctic. Range in the Canadian Arctic Archipelago limited. Common (where it occurs). Arctic Islands: Baffin, Southampton.
Ecology and habitat. Substrates, wet meadows, snow beds (occasionally), along streams, lake shores, slopes (boggy); imperfectly drained moist areas, on seepage slopes (and "slump areas"); acidic (to neutral, reported on granite, and in sphagnum bogs), or calcareous; sand, silt, moss. Throughout the species' range, L. wahlenbergii is typically found in tundra sphagnum bogs and in moss by brooks or lakeshores; wet slopes below snowbeds; in low wet Arctagrostis meadows; among large boulders on sandy silt near a Pucinellia phryganodes meadow. CAN 520296. In the Arctic Islands, it has been reported as "sparse" or "very common" in low wet Arctagrostis meadows and near Pucinellia phryganodes meadows. It is also found on wet, boggy slopes, sometimes below snow beds. A low arctic plant, the northernmost record in Canada occurs on Baffin Island, at Pangnirtung.
Illustrations. • Plant habitat. Mid-zone in photograph dominated by bownish plants of Luzula wahlenbergii. Nunavut, Baffin Island, Iqaluit, wet meadow of Sylvia Grinnell Park near the river, 25 Aug. 1997, S.G. Aiken 97–032, CAN. • Plant habitat. Dominant plants are Luzula wahlenbergii, 30–40 cm high. Nunavut, Baffin Island, Iqaluit, wet meadow of Sylvia Grinnell Park near the river, 25 Aug. 1997, S.G. Aiken 97–032, CAN. • Close-up of plant. Plant collected at Nunavut, Baffin Island, Iqaluit, S.G. Aiken 97–032, CAN. • Close-up inflorescence. Inflorescence with dehisced capsules. Nunavut, Baffin Island, Iqaluit, S.G. Aiken 97–032, CAN. • Arctic Island distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L.Consaul, R.L. Boles, R. Elven and M.E. LeBlanc. 2001 onwards. Flora of the Canadian Arctic Archipelago. Volume 1. Pteridophytes and Monocotyledons: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 16th March 2001. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Aiken, Dallwitz et al. (1999) should also be cited (see References).
