Linum marginale is a glabrous, often glaucous, perennial herb that typically grows to a height of 10–60 cm (3.9–23.6 in) and has a single stem or a few, branching at the base.

Flowering occurs in spring and summer and the fruit is a more or less spherical capsule 3–6 mm (0.12–0.24 in) in diameter and containing brown seeds.

[2][3][4] Linum marginale was first formally described in 1825 by Allan Cunningham in Barron Field's Geographical Memoirs on New South Wales.

[7] Native flax occurs in all Australian states, but not the Northern Territory.

It is widespread in grassland, woodland and forest, sometimes on the edge of swamps and is found in most regions of New South Wales and Victoria, but only in the south-west of Western Australia and the south-east of South Australia.