Barclaya is a genus of 3 - 4 species of flowering aquatic plants in the family Nymphaeaceae native to tropical Asia. Plants grow from egg-shaped tubers that produce short runners and a basal rosette of leaves. All leaves are submerged. Hydrostemma is the name that takes precedence over the name Barclaya, it having been published 6 months earlier. However, the name Barclaya has been "conserved" since it is much better known than Hydrostemma, and is therefore a synonym. In addition Hydrostemma is not accepted by all as the valid name.