The Hydrophyllaceae, or waterleaf family, are a family of flowering plants. Their taxonomic position is somewhat uncertain. Traditionally, and under the Cronquist system, they were treated as part of the order Solanales, as shown in the table at the right. However, newer systems remove them from that order. They are closely related to the large borage family, Boraginaceae, and have at times been placed in an order Boraginales with them, but some modern sources do not recognise this order, other do, like Gottschling et al. 2001. Thus recent recommendations are to merge this family with the Boraginaceae, but this family currently has no agreed placement at ordinal level.
Plants in this family may be annual or perennial herbs or shrubs, with either a prostrate or an erect stem. Most have a taproot. The flowers are bisexual, and normally radial, with 5 petals and 5 stamens. About 20 genera, containing around 300 species, are recognised; many of them are native to the western United States.
The family takes its name from the waterleaf (genus Hydrophyllum). Well known members of the family include the whispering bells (genus Emmenanthe), the baby blue eyes (genus Nemophila), and the scorpionweed (genus Phacelia).