[1] It is a perennial herb that typically dominates its environment by growing in dense clusters, called mats, in alpine bogs.

[2] Based on the current taxonomy for Asteliaceae, Astelia alpina's closest relatives include A. subulata, A. solandri, A. grandis, A. nervosa, A. chathamica, and A.

It is also closely related to A. hemichrysa, but a major branch point exists separating it from the other species of Astelia.

Like other species of Astelia, which grow in areas that are moist and humid, the ovary is full of mucilage, which is thought to function in pollen transmittance.

[1] Pineapple grass is commonly found in the subalpine and alpine areas of Tasmania and the Australian Alps.

[2] In these habitats, plants must be tough to survive the harsh wind exposure, hot sun in summer, and freezing in winter.

[4] The Tasmanian species typically dominates alpine sedgeland and is found on all mountains in Tasmania.

[12] Alpine herbland and sedgeland is typically dominated by Astelia alpina 10–20 years after a fire, a community that generally replaces deciduous and coniferous heath.

[2] The community it dominates, alpine sedgeland, is classified as Highland Treeless Vegetation, which is most threatened by fires, and pressures associated with bushwalkers.

[4] The 1889 book 'The Useful Native Plants of Australia records that "The fruit is sweet, and the bases of the leaves are eaten".