- Family: Bedstraw Family – Rubiaceae
- Growing form: Perennial herb. Rootstock short, vertical, gingery.
- Height: 25–45 cm (10–18 in.). Stem vertically branched, 4-edged, glabrous, gingery base.
- Flower: Corolla funnel-shaped, white, 3–4 mm (0.12–0.16 in.) broad, fused, long-tubed, 3-lobed. Calyx not present. Stamens 4. Gynoecium syncarpous, with 2 styles. Inflorescence a broad, lax compound cyme.
- Leaves: Whorled, lower, middle and upper parts with 6, 4 and 2 leaves respectively; stalkless. Blade linear–narrowly elliptic, with tapering tip, quite thick, with entire margins, slightly revolute.
- Fruit: 2-parted, glabrous, smooth, black schizocarp.
- Habitat: Stony hills, hedgerows, banks. Calciphile.
- Flowering time: July–September.
- Endangerment: Critically endangered, protected in all of Finland, including the Åland Islands.
Dyer’s woodruff is a demanding steppe plant which requires heat and highly calciferous soil. It can be found growing in a few places in Finland on the Åland Islands and in the south-west of the country. The clearing of fields probably decimated its stands and nowadays it is threatened by construction. As a light-loving plant the encroachment of bushes and other vegetation has decreased the amount of suitable habitat available. Dyer’s woodruff yields a red dye that is suitable for colouring textiles, and this valuable plant was already known to the Ancient Greeks and Romans. Blue woodruff (A. arvensis) grows casually in Finland and has also been used as a dye.
The third member of the family that grows in Finland is common madder, which was one of the most important textile dyes in Europe in its day. It yields a red dye which was known as Turkey red and was highly esteemed for its durability and beautiful bright colour. Common madder’s colour varies from wine to purple because it contains a mixture of different kinds of pigments.
The pigments in these plants can be found mainly in the roots, more precisely in its skin, bound to sugar compounds. In good conditions a dozen plants can produce around three grammes of fresh root mass, which weighs around half when it is dried. It takes about half a kilo of dried root to dye a kilo of cloth. It might seem that using the slim roots as a dye demanded an unreasonable amount of work, but despite everything cultivating and collecting the plants on a grand scale was significantly easier than collecting specific red-coloured insects or molluscs.