- Name also: Ladies’ Fingers, Kidney-vetch, Common Kidneyvetch, Woundwort
- Family: Pea Family – Fabaceae (Leguminosae)
- Growing form: Biennial or short-lived perennial herb.
- Height: 10–40 cm (4–16 in.). Stem procumbent–erect.
- Flower: Corolla zygomorphic, light yellow, sometimes red-tipped, 12–15 mm (0.48–0.6 in.) long, fused at base. Petals 5; the upstanding the ‘standard’, the lateral two the ‘wings’, the lower two united to form the ‘keel’, overall shape of corolla being butterfly-like. Calyx 5-lobed, oval, woolly, pale–purple tip. Stamens 10. A single carpel. Inflorescence spherical, raceme terminating stem, with subtending bracts, sometimes also stem leaves in axils or lateral branches.
- Leaves: Alternate, stalked–stalkless, stipulate. Lowest sometimes 1-lobed, upper leaflets in pairs, 1–5 pairs, with terminal leaflet, terminal leaflet usually larger than rest. Leaflets elliptic, with entire margins, sparsely hairy on top, underside with short and smooth hairs. Stipules small, falling.
- Fruit: 1-seeded legume, remains inside calyx.
- Habitat: Hillside meadows, meadows, roadsides, harbours, ballast soil deposits, light-filled pine forest ridges, gravel pits, rocky outcrops, river banks. Ssp. vulneraria is a calciphile.
- Flowering time: June–August.
- Endangerment: Protected in all of Finland except the Åland Islands.
Kidney vetch is a plant from the continental period that followed the Ice Age, and in the current climate which favours coniferous forests it has had to accept the small patches of steppe-like habitat that it can find in dry meadows and on ridges. It is a poor competitor and doesn’t do well when it is squeezed by other plants. It is very rare in Finland, but very diverse: there are at least four different subspecies which have adapted to different soil conditions and climates. Ssp. vulneraria is established in the Åland Islands and Häme, and it also grows casually in other areas of Finland. Ssp. polyphylla is endangered and can be found in a few places in south-eastern Finland. Ssp. carpatica, which is a western and central European variation of kidney vetch, is mainly a casual alien in Finland. Ssp. lapponica grows in Lapland on rocky outcrops and along river banks, but its habitat extends south to light-filled ridge slopes in Lohjanharju. Populations in different areas differ markedly from one another: plants in the south have longer stems, the leaves are more uniform along the stem, it has more leaves and leaflets, the leaflets and subtending bracts’ lobes are more sharp-pointed, and the tip of the calyx is not so strongly purple. This form is sometimes regarded as an independent subspecies ssp. fennica, which only grows in Finland.
Kidney vetch’s scientific name means ‘wound’, and the plant has apparently been used to treat wounds – although it is difficult to find grounds for this practice. If it has any medicinal properties they seem to have been forgotten about centuries ago, and the only reminder is in the name.