It is a Purple milk-vetch.

Scientific name: Astragalus danicus.

A low-growing perennial in the pea family, typically 5–30 cm tall, with slender, softly hairy stems. Its alternate, pinnately compound leaves bear numerous small, oval to oblong leaflets arranged in opposite pairs, plus a terminal leaflet. Compact, rounded to oval clusters of lilac-purple flowers rise above the foliage on long stalks. Each flower has a broad, upright banner petal with fine darker veins and a pale central area, two smaller wing petals, and a central keel. The flower bases are enclosed by conspicuously hairy greenish calyces. The fruits are short, inflated, hairy pods..

Purple milk-vetch forms a partnership with nitrogen-fixing bacteria in its root nodules, allowing it to obtain nitrogen from the air and grow in relatively nutrient-poor grassland..

The photograph shows compact clusters of pea-shaped, pale purple flowers with broad banners, whitish wing and keel petals, and densely hairy calyces. The surrounding pinnate foliage has many small, oblong leaflets. This combination strongly suggests an Astragalus milk-vetch, and the short, crowded flower heads and broad floral proportions are particularly consistent with Astragalus danicus. Similar Astragalus and Oxytropis species can be difficult to distinguish from a photograph; location and clear views of mature pods would help confirm the species.