Alpine aster

Aster alpinus, the alpine aster, is a low cushion- to mat-forming perennial herb in the family Asteraceae native to montane and alpine regions across Europe, the Caucasus, central and northern Asia, and disjunctly in the western United States. Plants form a tight basal rosette of leaves arising from a stout branching rootstock, with one to several unbranched flowering stems 10-30 cm tall. Basal leaves are oblanceolate to spatulate, 3-8 cm long and 5-15 mm wide, entire, dark green, and softly hairy on both surfaces; stem leaves are alternate, much smaller, linear-lanceolate, and progressively reduced upward. Each stem bears a single large solitary terminal flower head 3-5 cm across with 25-50 violet, lavender-blue, pink, or rarely white ray florets surrounding a flat disc of bright yellow tubular florets. The involucre is hemispherical with two or three rows of narrow, pubescent, often purple-tinged bracts of subequal length. Flowering occurs from June to August. Fruits are flat, pubescent, ribbed achenes 2-3 mm long crowned with a brownish capillary pappus of two unequal rows. The species inhabits alpine meadows, stony slopes, screes, and rock crevices, typically on calcareous substrates from 1500 to 3000 m elevation.