It is a tufted perennial herb with linear leaves and pale violet tepals.

Patersonia juncea is a tufted perennial herb that grows to a height of 7–30 cm (2.8–11.8 in) and forms a rhizome.

[2][3] Patersonia juncea was first described in 1840 by John Lindley in A Sketch of the Vegetation of the Swan River Colony.

[6] Rush leaved patersonia grows in forest, woodland mallee and scrub between Eneabba and Israelite Bay in the Avon Wheatbelt, Esperance Plains, Geraldton Sandplains, Jarrah Forest, Mallee, Swan Coastal Plain and Warren.

[2][3] Patersonia juncea is classified as "not threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.