- Name also: Wood Chickweed
- Family: Pink Family – Caryophyllaceae
- Growing form: Perennial herb. With runners, forms stands.
- Height: 20–50 cm (8–20 in.). Stem ascending–erect (flowerless shoots limp), abundantly branched, delicate, hairy.
- Flower: Corolla regular (actinomorphic), white, approx. 2 cm (0.8 in.) broad; petals 5, deeply 2-lobed (looks like 10 petals), 12–15 mm (0.48–0.6 in.) long, approx. twice as long as sepals. Sepals 5, glabrous–base hairy, membranous margins. Stamens 10. Gynoecium syncarpous, with 3 styles. Inflorescence a 10–50-flowered, 2-branched cyme; subtending bracts green.
- Leaves: Opposite, lowest long-stalked, uppermost stalkless. Blade ovate, lower cordate-based, upper blunt–wedge-based, with entire margins, light green.
- Fruit: Grey, 6-valved capsule.
- Habitat: Damp broad-leaved forests, rich mixed swamps, stream banks, springs, tall-growing meadows.
- Flowering time: June–July.
Wood stitchwort is the choosiest species in its family: it only grows on fertile and damp soil. It is regarded as a wonderful indicator of damp broad-leaved forests – often it is actually a question of perspective if the vegetation type is regarded as broad-leaved forest or rich swamp. Usually the species’ clear demands regarding its habitat are met at the bottom of valleys, and 100 years ago the plant was known as valley stitchwort in Finland. Despite its fragile qualities the species grows in some places in Lapland.
Wood stitchwort’s year begins early in spring: at the end of April the plant’s leaves are already full-sized and it begins to flower as May turns into June. The flower’s five petals (Stellaria means star) are doubly lobed to their base, so it is ten times crenellated, like a twinkling white star in the dim light of the forest. By July the flower is a distant memory as the seeds develop and eventually drop to the ground. In a suitable habitat wood stitchwort will expand into wide, dense stands which are almost impossible for other plants to grow among. The species owes its dominant status to its abundantly branched runners, which creep along the ground.
Wood stitchwort strongly resembles water chickweed (Myosoton aquaticum), but it is much more demanding with regards to its habitat. Additionally, it is erect or ascending when it is flowering, while water chickweed is always limp. Both have hairy stems. One sure way of telling them apart, although it requires precision, is the number of stigmas: wood stitchwort has 3 and water chickweed has 5.