Moehringia trinervia

Three-nerved sandwort is a small, slender, slightly pubescent annual growing 10 – 40 cm tall.[3][4] The leaves are 6 – 25 mm long[5] with three conspicuous longitudinal veins, although some leaves may have up to five veins.[4] 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.[6]^: 485 The flowering period is April until July.[4]

The plant is widely distributed in Britain and much of mainland Europe, although it is absent from the Hebrides, Orkney, and Shetland.[3] It favours fertile, well-drained soils in old lowland deciduous woodland and hedgerows, occurring up to 425 m.[5] In Britain, it is considered an ancient woodland indicator in southern England, East Anglia, and Carmarthen.[3][7] However, three-nerved sandwort may also be found in secondary woodland and can recolonize relatively rapidly after habitat disturbance.[8]

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.[9]

Three nerved sandwort superficially resembles chickweed but is distinguished from the latter by its deep longitudinal leaf veins and undivided petals. .