Senecio lugens is a member of the aster family (Asteraceae) with several yellow flowering heads and large basal leaves. Senecio lugens occurs across a wide area of Denali and is most common in subalpine meadows and floodplains near the mountains. Plants grow 5-35 cm tall stem arising from a thick rhizome. Basal leaves are highly variable: they are sessile (have no petiole), usually oblanceolate to elliptic in outline, hairless to sparsely hairy, with entire or finely toothed margins. Stem leaves are reduced. The flowering heads (2-12 per plant) are arranged in a branched inflorescence (corymb-like). The ray flower petals (ligules) are yellow, with involucralbracts below the blossom arranged in two rows, and having distinctive black or purplish tips (which is one good way to recognize this species, in combination with the multiple flowering heads and sessile basal leaves). Senecio lugens produces glabrousachenes.
Senecio lugens typically flowers mid to late-summer.
S. lugens is monoecious and insect pollinated. Seeds have an attached tuft of hairs and are wind dispersed.
Senecio lugens occurs only in North America, ranging from Alaska east into western Northwest Territory, and south through British Columbia and Alberta into Washington, Montana, and Wyoming. In Alaska, this species grows in suitable habitat statewide, except is absent from the southern Alaska Peninsula and the Aleutian islands. Senecio lugens is common in Denali, occurring in suitable habitat widely on both sides of the Alaska Range crest, particularly in hills and mountains and radiating into adjacent boreal areas along rivers.
In Denali, S. lugens is found at elevations 205 m to 1402 m with an average site elevation of 944 m. It prefers moderately steep slopes with an average slope angle of 12 degrees. It prefers south-facing to north-facing slopes.