Ninebark, Physocarpus opulifolius (L.) Maxim., should not to be
confused with sevenbark, which is a common name used for the native Hydrangea spp., where these
common names both refer to thin layers of exfoliating bark. Ninebark is
a deciduous shrub in the rose family as evident by the form of the individual blossoms in the terminal clusters of white flowers borne in late May to early June and followed by
capsules that turn from pale green to reddish before maturing to light brown. Ninebark is both easily grown from seed and transplanted since it is tolerant of a wide range of conditions, and once
it is established the shrub is nearly indestructible, yet
these characteristics do not give it a tendency to be invasive like similarly adaptable exotic plants.
If ninebark ever becomes overgrown all that is required is removal
of the offending stem(s) thus it can easily be maintained at
a desired size with periodic pruning, but if necessary severe pruning to the base of the shrub is possible like virtually all
native plants, other than most conifers, that either grow as a shrubs
or can be grow as coppiced trees. 
Ninebark can get leggy, but if this was a reason
not to plant something then both Nandina and Forsythia would similarly be virtually unheard of
in landscapes. I recall seeing one
local population, but by then I had identified several species new to me so ninebark was not as remarkable although it is still one of my favorites. The location of that population
is now in an Alabama Forever Wild tract in
