Annual or perennial herbs. Roots fibrous. Leaves grass-like or cylindric, sheathing at the base. Inflorescence terminal, umbellate or paniculate, the flowers solitary or in capitula; bracts leaf-like, scarious or membranous; bracteoles sometimes present. Flowers bisexual. Perianth segments 6, in two series, subequal, green or brown, usually membranous at the edges. Stamens 3 or 6. Carpels 3, joined; ovary superior, 1- or 3-locular; stigmas 3. Fruit a many-seeded loculicidal capsule.
Barcode of Life Data Systems (BOLD) Stats Specimen Records:992 Specimens with Sequences:1265 Specimens with Barcodes:961 Species:212 Species With Barcodes:197 Public Records:435 Public Species:142 Public BINs:0
The leaves are evergreen and well-developed in a basal aggregation on an erect stem. They are alternate and tristichous (i.e., with three rows of leaves up the stem, each row of leaves arising one-third of the way around the stem from the previous leaf). Only in the genus Distichia are the leaves distichous. The rushes of the genus Juncus have flat, hairless leaves or cylindrical leaves. The leaves of the wood-rushes of the genus Luzula are always flat and bear long white hairs.
The plants are hermaphroditic or, rarely, dioecious. The small flowers are arranged in inflorescences of loose cymes, but also in rather dense heads or corymbs at the top of the stem or at its side. This family typically has reduced perianth segments called tepals. These are usually arranged in two whorls, each containing three thin, papery tepals. They are not bright or flashy in appearance, and their color can vary from greenish to whitish, brown, purple, black, or hyaline. The three stigmas are in the center of the flowers. As is characteristic of monocots, all of the flower parts appear in multiples of three.
The dried pith of plants of this family was used to make a type of candle known as a rushlight.
The soft rush (Juncus effusus) is called igusa in Japanese and is used to weave the soft surface cover of tatami mats.
In medieval Europe, loose fresh rushes would be strewn on earthen floors in dwellings for cleanliness and insulation. Particularly favored for such a purpose was Acorus calamus (sweet flag), but despite its alternate vernacular name "sweet rush", it is a plant from a different monocotorder, Acorales.
^Burton, Alfred. Rush-bearing: An Account of the Old Custom of Strewing Rushes: Carrying Rushes to Church; The Rush-Cart; Garlands in Churches; Morris-Dancers; The Wakes; The Rush. Manchester: Brook & Chrystal, 1891; pp. 1-12