Lotus pedunculatus

Lotus pedunculatus (formerly Lotus uliginosus), the big trefoil, greater bird's-foot-trefoil or marsh bird's-foot trefoil, is a member of the pea family (Fabaceae).

It is a herbaceous perennial growing throughout Europe in damp, open locations. As one common name suggests, it is a larger plant than related Lotus species, growing 20 - 80 cm tall, with leaflets 10 - 25 mm long and 10 - 20 mm broad. Five to twelve golden-yellow flowers 10 - 18 mm long are borne in an umbel at the tip of the upright stem.

Unlike related species, the stem is always hollow, and the sepals turn back at their tips – these sepal tips form a characteristic "green star" at the end of the flower bud. The peak flowering period in the United Kingdom is June and July.

Lotus pedunculatus occurs in a wide range of neutral, damp, open habitats, including certain fen-meadow plant associations such as Juncus subnodulosus-Cirsium palustre fen-meadow habitat.

Lotus pedunculatus is also a host plant for ovipositioning of the wood white butterfly, Leptidea sinapis.