Asparagus trefoil

Lotus maritimus (also known as Tetragonolobus maritimus), the dragon's teeth or asparagus trefoil, is a low herbaceous perennial of the Fabaceae family native to central and southern Europe, North Africa, and western Asia and extending north into Britain and Scandinavia. From a slender taproot it produces prostrate to decumbent, branched, softly hairy stems up to thirty centimetres long. The alternate leaves are pinnately trifoliate, the three obovate to elliptic leaflets ten to thirty millimetres long, subtended by large, leaf-like stipules. From May through August the plant produces solitary or paired, large, pale lemon-yellow pea-flowers up to three centimetres long, often flushed with reddish veins, on long axillary peduncles. The most distinctive feature is the fruit: a long, straight, sword-shaped pod up to five centimetres long with four prominent longitudinal wings, giving rise to the common name. The plant favours damp, calcareous grassland and coastal shingle.