Eriophorum brachyantherum is a tussock-forming perennial sedge that occurs across boreal regions of Denali, primarily in permafrost-influenced areas north of the Alaska Range. This species has solitary white heads formed by the bristles surrounding the flowers and fruit. Plants occur most frequently in low-lying wet areas, and grow to 30-60 cm tall. Stems are slender, round, with 1-3 sheaths. Basal leaves are filiform with gray-brown basal sheaths. Flowers are aggregated into a dense solitary white head that tapers at the base. The bisexual flowers are subtended by scales. The scales are opaque, blackish, ascending, and ovate-lanceolate in shape. Bristles are yellowish-white. This species is typically mistaken for the more abundant (and larger) tussock-forming Eriophorum vaginatum, to separate the two, check whether the flowering head scales are opaque (E. brachyantherum) or translucent (E. vaginatum). Also, E. vaginatumtussocks reach a much larger size than the smaller tussocks of E. brachyantherum.
Eriophorum brachyantherum typically flowers in early-summer (early June).
E. brachyantherum is monoecious with wind pollinated bisexual flowers. Seeds are wind and water dispersed. Seeds can germinate quickly, often soon after dispersal.
Eriophorum brachyantherum has an incompletely circumpolar distribution ranging across northern Europe, Asia, and North America, but absent from Greenland. In North America E. brachyantherum occurs from Alaska east to Labrador through all Canadian provinces, but does not extend into the lower 48 states. In Alaska, this species occurs statewide except is absent from the southeast panhandle, the Aleutian chain and (apparently) the Yukon-Kuskokwim delta. In Denali, this species occurs in the boreal areas both north and south of the Alaska Range crest.
E. brachyantherum is a lowland species that is found in the park at elevation from 118 m to 1246 m with an average site elevation of 405 m. Although this species is observed on slopes as steep as 24 degrees, it prefers flat sites with an average slope angle of 2 degrees. For occurrences with slopes >5 degrees, E. brachyantherum is seen more commonly on north-facing slopes.
E. brachyantherum grows in acidic soils of lowland wet areas such as bogs, fens, tundra, and imperfectly drained permafrost. Soil pH for sites where this species was observed ranged from 4.1 to 6.1 with an average pH of 4.9.