Plants perennial; loosely cespitose or the culms solitary; rhizomes elongate, 0.3–1 mm thick. Culms 5–26(35) cm tall. Sheathsglabrous; ligules 0.4–1.3 mm long, obtuse; blades 2–25 cm long, 0.7–2 mm in diameter when rolled, involute to convolute, abaxial surfae glabrous, adaxial surface pubescent. Panicles 1–3(4.5) cm long, 0.3–0.5 cm wide, spikelike, with 1–2 spikelets per branch. Spikelets 3.5–5 mm long, green to purple; rachilla internodes about 0.1 mm long, glabrous. Glumes subequal, 2.9–4.7 mm long, shiny; lowest 2 florets staminate; lemmas sparsely hairy, acute or slightly notched, unawned or awned, awns to 1 mm long; bisexual lemma 2.9–4.4 mm long, with sparse, spreading hairs towards the tips; anthers 1.5–3 mm long. Caryopses about 2.5 long. 2n = 28.
Anthoxanum arcticum is a circumpolar coastal and lowland species that is present in Alaska, Canada, and Russia but not Greenland. It usually grows in wet tundra on acidic, peaty souls. In the warmest sections of the western high arctic, it is customarily rooted in mats of moss that are growing over carbonate substrates.