Grassleaf rush is a graminoid, 20-50cm tall. Its stems grow in dense tufts, its bulbous is thickened at the base. Its flowers are subtended by paired bracteoles, petals 2.3-3.3mm, oblong with broadly thin, dry margins, 3 stamens, nearly as long as the tepals. reddish-brown anthers that are much shorter than the filaments, usually soon shriveling. Fruits are incompletely 3-locular, the partitions not meeting in the center, somewhat turgid-inflated, 1.8-2.9mm long and nearly as thick. Principle blades are flat to involute, 1-3mm wide, with 2-3 prominent veins, lacking hard cross-partitions. Leaf sheaths have small, rounded, thin-dry, ear-shaped appendages. Plants are mostly 20-50cm tall, with 15-20 heads. Stems are densely cespitose, bulbous-thickened at the base.
Its height of 20-50cm, 15-20 heads, 1-3mm-wide main leaf blades that are flat to involute, and lack hard cross partitions, along with its densely cespitose stems with bulbous thickened at the base are among its distinguishing characteristics.