In our area, the family is represented by only one genus, Juncus.  Rushes are mostly perennials with basal leaves vertical, hollow, cylindrical to flattened, on an erect stem, and with 3-merous, green to brown flowers.  They arise from rhizomes (clone-forming stems) in water or moist soil.  The flower produces a 3-parted fruit capsule. In rushes, the basic flower structure is nearly the same as in Liliaceae, but the reduced perianth parts (tepals) are very small and bract-like, occurring in  terminal, head-like clusters. (In Cyperaceae (sedges), flowers have no perianth parts, but instead have bracts.  Cyperaceae are intermediate in evolution beween rushes and grasses. In many cases,  non-flowering plants in Cyperaceae are virtually indistinguishable from those of Juncaceae, suggesting a close relationship, supported by recent molecular work).  (Clarke p. 36)