[2] Its leaves have serrulate margins (very finely toothed) and are dark green and grey brown when dead.

The leaves of D. milliganii are similar to Richea pandanifolia which forms a large erect tree in rainforests but has small flowers arising from the axis of the stem and highly serrate (toothed) leaf margins.[3]D.

[2] It is found in harsh, open alpine sites on peaty or well-drained rocky soils in areas of regular snow lie.

Along with Isophysis tasmanica its presence is useful in determining communities of Tasmanian highland treeless vegetation, as it appears in western alpine heathland (HHW) and cushion moorlands (HCM).

[4] The first formal European description of D. milliganii was by botanist Joseph Dalton Hooker in his book Flora Tasmaniae (1860)[5] based on plant material collected at Mount Sorrell by Joseph Milligan,[1] a surgeon and amateur naturalist who attended an expedition to Macquarie Harbour in 1842.