Blue rush

Juncus glaucus Ehrhart ex Sibthorp

Herbs, perennial, cespitose, stooling, 4--10 (--12) dm. Rhizomes 3--5 mm diam. Culms terete, 1.5--3 mm diam. Cataphylls several. Leaves: blade absent. Inflorescences many flowered, open, 2--7 cm; primary bract terete, 10--25 cm. Flowers pedicellate; bracteoles ovate; tepals straw-colored to reddish brown, lanceolate, 2.7--3.5 mm, margins scarious; inner series loosely subtending capsule at maturity, shorter; stamens 6, filaments 0.8--1.5 mm, anthers 0.8--1 mm; style 0.3 mm. Capsules reddish brown to chestnut brown, 3-locular, 3-gonous-ovoid to widely ellipsoid, 3--4 mm, exceeding perianth. Seeds amber, obovoid, 0.3--0.5 mm, not tailed. 2n = 20, 38, 40.

Flowering and fruiting summer. Wet soils along streams, ditches, and on wet, sandy and peaty hillsides; introduced; Ont.; Mich., N.Y., Pa., Va.; Europe; Asia; Africa.