- Name also: Yellow Bedstraw, Yellow Spring Bedstraw, Wirtgen’s Bedstraw
- Family: Bedstraw Family – Rubiaceae
- Growing form: Perennial herb. Rhizomatous.
- Height: 20–60 cm (8–25 in.). Stem lower part 4-edged, upper part round, fine-haired.
- Flower: Corolla wheel-shaped, dark yellow, 3 mm (0.12 in.) broad, fused, 4-lobed. Calyx lacking. Stamens 4. Pistil of 2 fused carpels, styles 2. Inflorescence broad, narrowly conical, densely-flowered cyme. Flower with mild honey fragrance.
- Leaves: Regular (actinomorphic), usually 8 whorled leaves; stalkless. Blade needle-like, bristle-tipped, top shiny, underside white-haired, with entire margin, clearly revolute.
- Fruit: 2-parted, glossy, glabrous, black schizocarp when ripe, carpels round, 1.5 mm (0.06 in.) broad.
- Habitat: Sandy and dry meadows, juniper groves, rocky outcrops, banks, seashores.
- Flowering time: July–September.
- Endangerment: Vulnerable.
Lady’s bedstraw has adapted very well to dry habitats as its taproot is stout, deep-reaching and abundantly branched, and it is also rhizomatous. Its needle-like leaves are also a typical adaptation for xerophytes (plants that survive in dry environments). Lady’s bedstraw is Finland’s only yellow-flowered bedstraw – the others are more-or-less white.
Colourful lady’s bedstraw has been one of Finland’s most important wild dying plants: the root yields a splendid coral red colour and the flower turns things yellow. As a medicinal herb it has also been used to treat swelling, kidney and bladder troubles, and it has been administered both internally and topically. Its efficiency lies in its ability to contract membranous tissue and relieve cramps. If the patient is already in a place beyond hope, the sweet-smelling stems can be laid under the body in the coffin, for which reason it was earlier known in Finland as corpse-hay. According to an ancient and well-spread legend, lady’s bedstraw received its exceptional yellow colour when it was used by the Virgin Mary to soften the baby Jesus’s coffin. When dried, the species retains the scent of new mown hay. The name, lady’s bedstraw dates back to a time when palliasses were stuffed with straw.
Lady’s bedstraw has formerly been a common species in dry meadows and banks, but the disappearance of traditional farming methods has led to it becoming rare inland. It is also threatened by cross-breeding with its close relative upright bedstraw (G. album). This produces G. x pomeranicum, which has a clearly 4-edged stem, leaf blades that are hairy underneath, and creamy white flowers. In Finland the hybrid is classified as a harmful invasive species.