Flower:

Raceme or open branched cluster of 1 to 1½ inch stalked white flowers. Flowers have 5 petals each deeply cleft into 2 broad lobes with a prominent fringe at the base of the petal forming a collar at the opening of the floral tube. Male and female flowers are on separate plants. Female flowers have 5 styles that elongate and curl out over the collar.

Male flowers have 10 pale yellow stamens that extend to or a little past the opening of the floral tube. The calyx behind the flower is densely hairy, inflated, larger and more urn shaped on female flowers, strongly veined and ridged, 10-veined on males and 20 on females, green or often deep maroon, especially on males. Flowers are odorous, open in the evening and close by noon, sometimes later on cloudy days.

Leaves and stems:

Leaves are 1¼ to 4 inches long,  1/3 to 1½ inches wide, lance-shaped to broadly elliptic, toothless, with short stalks on lower leaves becoming smaller and stalkless higher on the stem. Stems and leaves are hairy becoming glandular and sticky in the upper plant.

Fruit:

Fruit is an urn shaped capsule, about ½ inch long, turned up, the opening ringed with 10 upturned or spreading teeth, tan colored eventually turning dark brown. The capsule is covered in a brown papery wrapping that dries up and falls away when the capsule opens.

Inside the capsule are numerous black seeds just over 1 millimeter long, somewhat kidney shaped and covered in a pattern of tiny pimples. A single female plant is capable of producing up to 24,000 seeds.

Notes:

A widely distributed weedy species from Europe, White Campion is common in waste places and disturbed sites in both urban and rural areas. A very similar species is Night-flowering Campion (Silene noctiflora), which has slightly smaller perfect flowers (both male and female parts on the same flower) with only 3 styles, narrower petal lobes, and only 6 teeth on the opened capsule. Another species commonly called Bladder Campion is Silene vulgaris, which is mostly hairless overall with a smooth calyx and has long protruding stamens with purplish tips.