Alabama Snow-Wreath

Neviusia alabamensis
An upright but broad, suckering, deciduous shrub, reaching a maximum size of 6.5 x 10 feet, that is a close relative of Kerria. Some records include: fastest growth rate - 4 feet; largest on record - 8 x 11 feet. This is one of 2 species in the Neviusia genus and it is native to the southeastern U.S. ( central Arkansas to southeast Missouri to the Smoky Mountains in Tennessee; south to central Mississippi to central Alabama to northwest Georgia ) where it is endangered with extinction in the wild.
The alternately-arranged, saw-toothed, ovate leaves are up to 3.5 inches in length. The very attractive foliage is mid-green above, downy beneath. The foliage turns to yellow during autumn.
The very showy, fluffy, white flowers, up to 0.5 inches wide, are borne mid to late spring.
Hardy zones 4 to 8 in full sun or partial shade on fertile, light, well drained soil. Easy to grow and tolerant of drought though looks better if irrigated deeply once weekly during dry spells. Cut out tired or dead stalks at the base after blooming to tidy appearance and enhance vigor ( similar to pruning of most Spirea ).
Propagation can be achieved from seed, layering ( often occurs naturally in the wild ), cuttings or division.

* photos taken on June 30 2013 @ U.S. National Arboretum, DC

* photos taken on Apr 17 2016 @ U.S. National Arboretum, DC

Neviusia cliftonii ( Shasta Snow-Wreath )
Very similar to the Alabama Snow-Wreath and has a tiny native range in the Mount Shasta region of California. It was originally discovered as recently as 1992.
Hardy zones 6 to 8.

Neviusia dunthornei
Presumed to be extinct but is known from fossils to have occured in the Okanagan Highlands in interior British Columbia and Washington State, mostly on shale deposits.