Moehringia trinervia, commonly known as apetalous sandwort or three-nerved sandwort, is a herbaceous flowering plant in the family Caryophyllaceae. A native of Eurasia, it has been introduced into North America.[1]
Three-nerved sandwort is a small, slender, slightly pubescent annual growing 10 – 40 cm tall.[2] [3] The leaves are 6 – 25 mm long[4] with three conspicuous longitudinal veins, although some leaves may have up to five veins.[3] The flowers measure approximately 6 mm in diameter, with each bearing ten stamens and three styles. The three-veined sepals are longer than the petals.[5] The flowering period is April until July.[3]
The plant is widely distributed in Britain and much of mainland Europe, although it is absent from the Hebrides, Orkney, and Shetland.[2] It favours fertile, well-drained soils in old lowland deciduous woodland and hedgerows, occurring up to 425 m.[4] In Britain, it is considered an ancient woodland indicator in southern England, East Anglia, and Carmarthen.[2] [6] However, three-nerved sandwort may also be found in secondary woodland and can recolonize relatively rapidly after habitat disturbance.[7]
A Polish study in the Niepołomice Forest found that three-nerved sandwort accumulated high amounts of heavy metals from pollutive industrial emissions in its tissues, especially of cadmium. The conclusion was that a high level of heavy metal ions in three-nerved sandwort reflects levels of heavy metal pollutants in the soil and atmosphere, so that this plant may serve as a useful bioindicator of environmental pollution with such metals.[8]
Three nerved sandwort superficially resembles chickweed but is distinguished from the latter by its deep longitudinal leaf veins and undivided petals. .