Free hypanthium absent. Androecium exclusively of fertile stamens . Carpels reduced in number relative to the perianth to increased in number relative to the perianth. Polar nuclei fusing prior to fertilization. Endosperm formation cellular, or nuclear.
Capsules loculicidal .
Physiology, biochemistry . Ursolic acid absent. CAM recorded in Philadelphus - Troughton et al. 1974. Geography, cytology . Holarctic and Paleotropical.