Festuca rubra is a creeping rhizomatous grass that occurs commonly in floodplains and open soil and gravels on slopes and ridges from the boreal to alpine zones in Denali. Plants grow 15-60 cm tall with upright panicles from fibrous roots in loose tufts, spreading by rhizomes. Stems are glabrous and curved at the base. Leaves are mainly basal, narrow, stem leaves often withering. Leaves are involute and less than 3 mm wide. Ligules are membranous. The inflorescence is linear, but opens into a pyramidal shape during flowering. Spikelets are 6-11 mm long, greenish or purplish, containing several bisexual flowers. Spikelets have two glumes. The lemmas are 5-nerved with awns 0.5 to 3 mm long. The anthers are 2.5-3.5 mm long. The fruit is single-seeded, indehiscent and dry. This species grows by rhizomes, unlike most other local fescues. The closely related F. richardsonii (sometimes considered a subspecies) is distinguished by its densely hairy lemmas.
Festuca rubra is a perennial species that typically flowers in mid-summer.
Festuca rubra is monoecious with bisexual florets. It is wind-pollinated and its fruits are wind-dispersed. It also spreads vegetatively via rhizomes, and can form a dense turf.
Festuca rubra has been cultivated as a turf grass, and is widely used in revegation efforts, including those in Denali National Park and Preserve.
Festuca rubra is a circumboreal species, occurring across much of North America and Eurasia. In North America, this species occurs throughout Canada and the U.S., although not reaching the southeastern United States. Festuca rubra occurs in every geographic region of Alaska. Festuca rubra is widespread in suitable habitats across Denali, occurring in scattered locations both north and south of the Alaska Range crest.
Festuca rubra is primarily a subalpine and alpine plant in Denali, most common above 1100 meters. Specimens found on southern aspects occupied a wider range of elevations, but were typically found on shallower slopes. Festuca rubra occurs on all angles, but prefers very steep slopes (> 28 degrees).