Juncus L.
Bog rush.
Juncaceae, rush family.
Plants caespitose, or not caespitose; with erect unbranched stems arising close together, or with stems growing in more or less straight rows; less than 15 cm high, or more than 15 cm high; 3–50 cm high. Ground-level or under-ground stems horizontal, or not developed horizontally or vertically underground; rhizomatous, or stoloniferous; elongate, or compact. Aerial stems erect; circular or oval in cross-section; glabrous. Leaves mostly basal, or distributed along the stems (absent in Juncus arcticus); alternate; deciduous, or marcescent. Petioles absent. Sheaths with the margins fused only in the lower part, or with the margins not fused. Ligules absent. Blades 30–250 mm long; 0.3–4 mm wide; straight; linear; with blade auricles, or without auricles; circular in cross section, or involute, or folded; with parallel veins; adaxial surface glabrous. Blades abaxial surface glabrous. Leaf apices acuminate.
Flowering stems with leaves, or without leaves; glabrous. Leaf or reduced bract closely associated with the base of the inflorescence present; conspicuous and leaf-like, or reduced, or scale-like. Flowers solitary, or in inflorescences (usually). Inflorescences head-like; inflorescence dense; inflorescence 0.4–6 cm long. Flowers per inflorescence 1–10; small, less than 5 mm in diameter or length, or medium-sized, 5–15 mm in diameter or length; sessile or subsessile. Floral bracts apex entire. Calyx sepals 3; free; yellow, or brown; scarious; glabrous. Petals 3; free; yellow, or brown; lanceolate; unlobed; 2.4–6.5 mm long; shorter than the calyx, or same length as the calyx. Stamens 6. Anthers 0.7–1.5 mm long. Carpels syncarpous; 3. Gynoecia superior. Styles completely fused. Styles 1. Stigmas per style 3. Ovules 10–100. Fruit with calyx persisting; a capsule; ellipsoid, or ovoid, or elongate-cylindrical, or obovate; not distinctly flattened; dehiscent; 2.5–8 mm long; 1–3 mm wide; sessile; dry; yellowish, or black, or brown. Seeds 10–100; 0.4–3.5 mm long; brown; smooth.
Chromosome information. 2n = 30, 60, 80, 84, 120, 130–134.
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).