A perennial or rhizomatous geophyte herb, Eurychorda complanata exhibits a graminoid growth form with tufted or shortly creeping rhizomes, and erect culms ranging from 20–120 cm (7.9–47.2 in) in height and 0.8–3.5 mm (0.031–0.138 in) in diameter.

[4][5][6] Leaves are reduced pale, glabrous sheaths along the stem with acute apices, approximately 10–25 mm (0.39–0.98 in) long.

[4] It flowers in summer (November, December, January, February) and has dry dehiscent capsule fruit.

[4] Eurychorda complanata thrives in waterlogged peaty vegetation from sea level to sub-alpine areas and is a common species in button grass sedgeland communities.

[8][9] The species was then formally described and named in 1998 by Barbara Gillian Briggs & Lawrence Alexander Sidney Johnson.