There are about 60 species of shrubs in this
genus. Most are native to North America,
Central America, Asia and Southeast Europe.
The
genus name comes from Pharoah Ptolemy II
Philadelphus (308-246 B.C.). Aristotle name a
tree after him but that tree is now unknown.
Later someone took the name and applied it to
this species of shrubs. It has nothing to do
with the City of Philadelphia, PA.