(Silene uniflora)
Silene uniflora is a herbaceous perennial plant, similar in appearance to the bladder campion (Silene vulgaris) but with flowers generally solitary. It is generally prostrate, mat-forming. The leaves are linear, grey-green glabrous and glaucous in opposite and decussate pairs, the flowers white with five deeply notched petals, the 5 sepals fused and inflated to form a bladder. Silene uniflora is a maritime species, almost confined to Iceland and the Atlantic and Baltic sea coasts of the Azores, Cape Verde islands western Europe. In Britain it also occurs rarely in the mountains.