Saxifragaceous \Sax`i*fra*ga"ceous\, a. (Bot.) Of or pertaining to a natural order of plants (Saxifragace[ae]) of which saxifrage is the type. The order includes also the alum root, the hydrangeas, the mock orange, currants and gooseberries, and many other plants.

Source: Webster's Revised Unabridged Dictionary (1913)