Menyanthaceae

Perennial non-woody (herbaceous) wetland or aquatic plants that have stalks (petioles) on their alternate leaves and 5 petals that are partially fused at the base and folded inward with the edges touching but not overlapping; includes Buckbean (also called Bogbean) and Floating-heart.

Stamens and petals 5 each, like parts partially fused at the base and forming a short tube. The free portions of the sepals and petals are called lobes. Inner surface of petals densely adorned with white hairs in Buckbean. Stamens are attached to the petal tube and alternate with the petal lobes. Carpels 2 and fused, stigma 2-lobed. Fruit a capsule.

Leaves, alternate, simple and heart-shaped (Floating-heart), or in threes (Buckbean). Have creeping underground stems (rhizomes).