Stellaria alsine

Bog stitchwort is a rhizomatous perennial plant, with smooth, four-angled stems up to 40 cm (16 in) tall.[1] Its leaves are opposite and narrow, up to 13 mm (0.51 in) long, with untoothed margins but a few marginal hairs towards the leaf-base.[1] The flowers are borne in cymes of 1–5, arising from the axils of the higher leaves. Each flower is around 6 mm (0.24 in) in diameter, with 10 stamens, 3 stigmas, five lanceolate–triangular, green-coloured but scarious-margined sepals, and five slightly shorter white petals.[1] The petals are divided into two almost to their base with the two halves angled apart,[1] so that the two halves of each petal lie over parts of adjacent sepals.[2]

Bog stitchwort grows in various types of wetland habitat; in the British Isles, it is especially characteristic of areas poached by cattle.[3] It flowers in spring and early summer.[1]

Bog stitchwort is widespread in central and western Europe, but is rarer in eastern and southern Europe and the northern half of Scandinavia.[4] It is thought to be native to eastern parts of North America, but to be an introduced species in the Pacific Northwest.[1] It has also become naturalised in South America, in Asia, where it has become a weed of rice fields,[5] and on the Kerguelen Islands in the southern Indian Ocean, where it is an aggressive invasive species.[6]

Stellaria alsine was first described by Johann Friedrich Carl Grimm in 1767.[1] The species has also been widely referred to under the junior synonym Stellaria uliginosa.[7]

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