Probably from Greek sialon, “saliva,” from a gummy exudation on the stems; or named for Silenus, intoxicated foster father of Bacchus (god of wine) who was covered with foam similar to the glandular secretions of many species of Silene
Bladder campion is a European native, brought to North America, where it is now a common weed.
Identification: Plants are
1½-3½′ (45-106 cm) tall, with hairy, jointed stems. Leaves are oval to narrow, 4″ (10 cm) × ¾″ (2 cm).
Flowers are white or pink, ¾-1″ (1.9-2.5 cm) in diameter, with five deeply notched petals. Flowers open in the evening and close by noon. The calyx at the base of each flower is bulbous, like a little balloon, sometimes called the bladder. It is lined with ten prominent dark green or purplish "nerves." Seeds are small, rounded, and rough.
White campion closely resembles bladder campion:
6/16/2010 · Nashua River Rail Trail, Groton Center, Groton, Massachusetts · ≈ 3 × 4½″ (7.9 × 11 cm)
6/13/2017 · Old Long Loop, Beaver Brook Conservation Area, Hollis, New Hampshire · ≈ 5 × 3½″ (13 × 8.7 cm)
1½-3½′ (45-106 cm) tall, with hairy, jointed stems
Flowers
White or pink, ¾-1″ (1.9-2.5 cm) in diameter, with five deeply notched petals. Flowers open in the evening and close by noon. The calyx at the base of each flower is bulbous, like a little balloon, sometimes called the bladder. It is lined with ten prominent dark green or purplish "nerves"