A perennial plant with procumbent, branched rhizomes and long roots, it has a weak climbing stem. With inflorescences on long stalks, the crown is colored purple and violet. It flowers from May to August. The fruit is an indehiscent pod. It grows on humid to wet meadows and bogs, often in communities of tall rushes and reeds. The Marsh Pea is listed among the critically endangered species of our flora.