Astragalus alpinus

Scientific profile

Astragalus alpinus is a low-growing, herbaceous perennial reaching about 9 cm in height. Its compound leaves typically bear (4–)7–12 pairs of veined, broad leaflets that are hairy at least on the undersides; ovate stipules 3–5 mm long are present at the leaf bases. The short, stalked racemes carry 5–15 pea flowers, each 10–14 mm long, with a bluish standard, white wings and a violet keel. The flower stalk is usually longer than the accompanying leaf. The calyx is 4–5 mm long, truncate at the apex. The inflated pod, 8–15 mm long by 3–5 mm wide, is at first covered in black hairs. Seeds are tiny (diaspore mass 2.15 mg). The plant forms arbuscular mycorrhizal (AM) associations. It is native in Great Britain, growing in full sun on nutrient-poor, fresh, neutral to slightly acid soils under cold alpine conditions, and is red-listed. It offers a moderate pollen and nectar reward (value 2) to flower-visiting insects.