Androsace septentrionalis is a small herb with a basal rosette of leaves and several narrow umbels of tiny white flowers. Plants are annual or biennial, growing 5-20 cm tall from shallow roots in open soil in warm slope positions from lowlands into lower alpine zone (uncommon in Denali). Leaves are lanceolate, margins entire or slightly toothed, often reddish-green, 0.5-5 cm long. The comparatively tall stems are leafless, erect, a few to many from a plant, usually of unequal heights. Stems are glabrous or pubescent with short, branched hairs. The inflorescences are umbels (many flowers radiating from one point) with 5-20 small white flowers. The petals are fused into a five-lobed bell 3-5 mm long, white at the tips with a yellow center. Flowers develop into rounded 5-valved capsules. Androsace septentrionalis differs from Androsace chamaejasme in that plants lack long, unbranched hairs.
Androsace septentrionalis is an annual or biennial plant. An individual germinates before winter, overwinters, and continues to develop and flower through the next the growing season before dying. Plants begin to grow and flower shortly after snowmelt, flowering for a month in the Rockies (Inouye et al. 2003). The phenology is variable by year, tightly correlated to environmental variables.
Androsace septentrionalis is monoecious with bisexual flowers. Other species of Androsace are insect-pollinated (Mosquin 1971). Flowers are likely self-incompatible. The fruits are dry capsules with many seeds. Seeds are reported as both dormant and non-dormant (Amen 1966).
Androsace septentrionalis is a circumpolar species that occurs in hills and mountains throughout northern areas of the globe. In North America, this species occurs from Alaska across Canada to Greenland, south through the western half of the United States to Texas. In Alaska, Androsace septentrionalis occurs widely including in the interior hills, Alaska Range, Seward Peninsula, Brooks Range, North Slope, and the Chugach, Wrangell and St Elias mountain ranges. Androsace septentrionalis is known from a handful of mid-elevation localities in Denali, all located in the foothills in the northeastern corner of the Park.
All specimens recorded were from above 500 m, with an average altitude of 880 m. Most specimens were found on south facing slopes. This species prefers low to moderately steep slopes; the average site had an incline of 18 degrees.