About Cerastium diffusum Pers.
Cerastium diffusum, commonly known as fourstamen chickweed or sea mouse-ear, is a species of flowering plant belonging to the pink and carnation family, Caryophyllaceae. It is an annual herb that grows up to 30 cm high, and is found in western Europe and northern Africa. It occurs mainly in coastal areas of Algeria, the Baleares, Belgium, Corsica, Denmark, France, the Faroe Islands, Germany, Great Britain, Ireland, Italy, Libya, Morocco, Netherlands, Norway, Portugal, Sardinia, Sicily, Spain and Sweden. Its flowers appear between March and May, and typically have 4 petals (rarely 5), plus 4 or 5 stamens. The plant’s petals are much shorter than its sepals. Its leaves are opposite and sessile, meaning they have no petioles. All of its sepals and bracts are green, with no pale margins. When mature, its fruit petioles are upright and spread out diffusely. Two infraspecific taxa of the species are currently recognized: Cerastium diffusum subsp. diffusum and Cerastium diffusum subsp. gussonei (Tod. ex Lojac.) P.D.Sell & Whitehead. This species was first published in 1805, in Synopsis plantarum 1, on page 520.
