Perennial herb to 60 cm high with shortened underground stems (rhizome) to produce a clumping habit.
Leaves are bluish-grey and generally tightly clustered, hairless, and irregularly toothed.
Flowers are yellow and resemble the Common Garden Sow Thistle. However, Dune Thistle flowers are larger and their distribution is confined to coastal sand dunes.
Seeds are typically produced in greatest abundance in late spring/early summer when there is still sufficient rainfall. The fruiting structure of each seed is technically known as a cypsela (or an achene). Each seed has a featherlike appendage attached which aids seed dispersal by coastal breezes.

Indigenous uses as provided by the Wathaurung Aboriginal Corporation: The leaves of this plant are edible and is baked with meats in an earth oven.