- Name also: Purging Flax
- Family: Flax Family – Linaceae
- Growing form: Annual or biennial herb.
- Height: 5–25 cm (2–10 in.). Stem quite delicate, glabrous, round. Buds nodding.
- Flower: Regular (actinomorphic), usually max. 1 cm (0.4 in.) across. White, separate, 4–5 mm (0.16–0.2 in.) long, ovate, petals 5 with entire tips. Petals’ base with yellowish spot. Sepals 5, separate, linear, about 3 (0.12 in.) mm long. Stamens 5. Pistil of 3 fused carpels. Inflorescence a many-flowered cyme.
- Leaves: Opposite. Blade lanceolate–narrowly obovate, 1-veined, 1 cm long.
- Fruit: Spherical, 2–3 mm (0.08–0.12 in.) long 4-parted capsule, each compartment with 2 seeds.
- Habitat: Coppices and sea-shore meadows, dry pastures, rocky outcrops. Calciphile.
- Flowering time: June–August.
Flax has been cultivated for at least 5,000 years for its fibre and also its oil. Worldwide, the Flax family has 16 genera comprised of less than 200 species. In the Nordic countries there are 2 genera and 4 species. The best-known and largest genus in the family is Linum, and its most famous member is common flax, which has been grown for fibre and oil. Fairy flax grows in south-western parts of Finland on coppices and seashore meadows in quite wet as well as dry habitats. Human activity has apparently increased the size of its habitat in e.g. grazing land. Fairy flax likes calciferous soil and is regionally endangered. Fairy flax is an annual or biennial. One-year-old plants are usually unbranched, while 2-year-old plants develop a many-branched flowering stem in their second year.
Fairy flax’s relative, common flax (linseed) is a taller (30–70 cm) annual with larger flowers. Typically it can be found near railway stations and on waste lands. Common flax’s flowers are blue (sometimes white) and 3–5 cm wide. Leaves are alternately, and capsule close to 1 cm wide.