Lathyrus palustris L.

Perennial, Herbs, Plants with rhizomes or suckers, Nodules present, Stems or branches arching, spreading or decumbent, Stems prostrate, trailing, or mat forming, Stems less than 1 m tall, Climbing by tendrils, Stems solid, Stems or young twigs glabrous or sparsely glabrate, Stems winged or with decurrent stipules, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules green, triangulate to lanceolate or foliaceous, Stipules persistent, Stipules free, Stipules cordate, lobed, or sagittate, Leaves compound, Leaves even pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 4, Leaflets 5-9, Leaves glabrous o r nearly so, Flowers in axillary clusters or few-floweredracemes, 2-6 flowers, Inflorescences racemes, Inflorescence axillary, Bracts very small, absent or caducous, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals pinkish to rose, Petals blue, lavander to purple, or violet, Banner petal ovoid or obovate, Wing petals narrow, oblanceolate to oblong, Wing petals auriculate, Wing tips obtuse or rounded, Keel abruptly curved, or spirally coiled, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style flattened, Style hairy, Style hairy on one side only, Style persistent in fruit, Fruit a legume, Fruit unilocular, Fruit freely dehiscent, Fruit elongate, straight, Fruit exserted from calyx, Valves twisting or coiling after dehiscence, Fruit glabrous or glabrate, Fruit 3-10 seeded, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black.