Usually 2-3 bracts, lanceolate to narrowly ovate, 1.5-3 mm long, often purplish-black.
It flowers in July.
It is a perennial herb with a very short rhizome and numerous fibrous roots. The leaf rosettes are less than 1.3 cm tall, usually forming dense cushion-like clusters, with brownish withered leaves at the base.
The calyx is cup-shaped, 3-3.5 mm long, glandular on the outside, often purplish-black. It is split to the middle or slightly beyond, with rectangular to lanceolate or narrowly elliptic lobes, acute or obtuse at the apex, sometimes with small teeth.