Sagina procumbens is a species of flowering plant in the pink family known by the common names procumbent pearlwort,birdeye pearlwort and matted pearlwort. It can be found throughout the Northern Hemisphere and parts of South America. It is a common weed of many environments. It can be found in wild and disturbed habitat, especially moist areas. It can sometimes be seen growing in lawns or in cracks in the sidewalk. This is a perennial herb forming clumps or mats of hairless green herbage, sometimes vaguely resembling a patch of moss. The leaves are linear and up to 1 or 2 centimeters long. The inflorescence is a solitary flower with four or five sepals and four or five small white petals, but the petals are sometimes absent.
In 1998 numerous well-developed plants were found on the UNESCO World Heritage Site of Gough Island where it is an introduced species. Given the island's remoteness seeds were most likely introduced from visitors' footwear and/or clothing. Without control the plant will very likely transform the ecosystem of the island's uplands - as it has already done on the Prince Edward Islands where it has spread at a rate of 100m to 300m per year and is now considered beyond control. Eradication programs on Gough Island are ongoing and are expected to require years of 'concerted effort'.
It is said to have been the first plant on which Christ set his foot when he came to Earth, or when he rose from the dead. In the highlands of Scotland it was supposed to have derived supernatural powers from having been blessed by Christ, St Bride and St Columba. A spray of it hung from the door lintel gave protection against fairies, especially those who made a practise of spiriting people away. If pearlwort were stuck in a bull's fore-hooves, the cows with which it mated and the calves and the milk they produced were safeguarded from ills. If a cow ate the herb, it's calves and milk, and all who drank the milk, were also protected against fairies. For the young village maiden, pearlwort brought a bonus. If drunk in an infusion, or used merely to wet the lips, it would attract her favoured lover, and if a piece of it were in the girl's mouth when she kissed him, he was bound to her for ever.