Common Name: 

Some 60 species of, usually deciduous, shrubs with peeling bark.  Axillary buds may be exposed or hidden within the base of the petiole.  Leaves usually simple and opposite.  Flowers solitary or in clusters, usually strongly fragrant, 4 sepals and 4 petals, numerous statmens.  Fruit a capsule with many seeds.  Native to North and Central America, Caucasus, Himalaya, China, and eastern Asia.
Philadelphus: Greek word meaning brothery love; or after Ptolemy Philadelphus (ruled 285-246 BC), a patron of the arts and sciences.

Hyrangeaceae (Philadelphaceae)