Herbs, perennial, rhizomatous, 5--9 dm. Rhizomes 2--3 mm diam. Culms erect, 2--6 mm diam. Cataphylls 0 or 1--2, straw-colored, apex narrowly acute. Leaves: basal 1--3, cauline 2--6, straw-colored; auricles absent; blade 10--40 cm x (3--)7--12 mm. Inflorescences panicles or racemes of 20--50 heads, 2--14 cm, erect or ascending branches; primary bract erect; heads 15--70-flowered, obovoid to globose, 7--11 mm diam. Flowers: tepals green to brown or reddish brown, lanceolate, 2.4--3.7 mm, nearly equal, apex acuminate; stamens 6; anthers ½1/2 to equal filament length. Capsules slightly exserted, chestnut to dark brown, 1-locular, ellipsoid, 2.4--3.8 mm, apex acuminate, not beaked. Seeds elliptic to obovate, 0.4--0.6 mm, not tailed. 2n = 40.
Fruiting early summer--fall. Salt marshes, moist areas, ditches, springs, lake and stream shores; 500--1600 m; Ariz., Calif., Nev., N.Mex., Utah; Mexico (Baja California).
This species and the next (Juncus ensifolius) are closely related and have been treated as members of a single species (J. xiphioides) by Engelmann. Until a study of the complete subgenus is done, I amwe are hesitant to use a varietal name (J. xiphioides var. triandrus) for the widespread western taxon J. ensifolius.
FNA 2000, Wiggns 1964, Martin and Hutchins 1980, Kearney and Peebles 1969
Common Name: irisleaf rush Duration: Perennial Nativity: Native Lifeform: Graminoid General: Perennial from rhizomes 2-3 mm in diameter, 50-90 cm tall, rhizome widely creeping. Vegetative: Culms erect, greatly compressed laterally, acutely 2-edged, moderately transversely septate, sheaths with membranous margins, no auricles; blade 10-40 cm long by 6-12 mm wide. Inflorescence: Many headed compound panicle or raceme of 20-50 heads, 2-14 cm, on erect or ascending branches, each head 15-70 flowered, obovoid to globose 7-11 mm; tepals green to brown or reddish brown, lanceolate, 2.5-3.5 mm, nearly equal; 6 stamens; capsules slightly exserted, chestnut to dark brown, 1-locular, ellipsoid, 2.5-4 mm, not beaked. Ecology: Found in moist to marshy soils along streams, lakes, and marshes or meadows from 3,500-6,500 ft (1067-1981 m); flowers June-August. Notes: Distinctive with the equitant leaves, which with the compression almost appear to be Iris leaves. Ethnobotany: Unknown Etymology: Juncus comes from the Latin jungere, to join or bind, while xiphioides comes from Greek name xiphos sword for the shape of the leaves, the whole work means having the appearance of Xiphium the Greek name for gladiolus. Synonyms: None Editor: SBuckley, 2010