Saxifraga is the largest genus in the family Saxifragaceae, containing about 440 species of holarctic perennial plants, known as saxifrages or rockfoils. The Latin word saxifraga means literally "stone-breaker", from Latin saxum ("rock" or "stone") + frangere ("to break"). It is usually thought to indicate a medicinal use for treatment of urinary calculi (known as kidney stones), rather than breaking rocks apart.The genera Saxifragopsis (strawberry saxifrage), and Saxifragella are sometimes included in Saxifraga. In recent DNA based phylogenetic analyses of the Saxifragaceae, the former sections Micranthes and Merkianae are shown to be more closely related to the Boykinia and Heuchera clades, and the most recent floras separate these groups as the genus Micranthes.