Hydrostachyaceae

Aquatic annual, rarely perennial, herbs, dioecious (in ours). Stipules present, small. Leaves submerged, basal, ± fern-like in appearance, 2-3-pinnatisect (in ours); petiole and rhachis densely covered with warty to tongue-shaped protuberances. Inflorescence emergent, spicate, (resembling the fruiting spikes of Plantago major). Flowers solitary in axils of spirally arranged bracts. Calyx and corolla 0. Male flowers a single stamen. Female flowers with a 1-locular superior ovary; styles 2. Capsule enclosed in the persistent bract, 2-valved.