Height: 8"-20" (20-50cm). Flower: 3/4" (2cm) in diameter; regular, with globular calyx, 5 petals with deep clefts, 10 stamens, 3 styles; several in cyme. Leaves: Lanceolate or ovate; entire: opposite. In bloom: April-August. Habitat-Range: Roadsides, borders of fields; throughout.
The sepals form a sac which is narrower at the open end than in the middle; hence the reference to a bladder in the common name. Early writers say that a thick, downy-leaved plant of this family was dried and used by soldiers in the field as wicks for their lamps. Snowy Campion (S. nivea) is a similar species that grows chiefly in the western part of our range but its calyx is bell-shaped and the petals are merely notched.