This annual plant is endemic to North-Central Sardinia (Campeda, Macon, Orune etc.). It grows in wet meadows and in ephemeral ponds, between 500 and 600 m. In the IUCN regional Red List it is cited as a critically endangered species (Conti et al., 1997).The genus name derives from the Greek 'keras' (horn), due to the elongated shape of the capsules; the species name refers to the habitat. Flowering period: April to May.

Italian name(s): Cerastio palustre (Italia), Peverina palustre (Italia).