Vascular Plants of North Carolina
Account for Smooth Hydrangea - Hydrangea arborescens   L.
Members of Hydrangea with account distribution info or public map:
Google Images
Section 6 » Order Rosales » Family Hydrangeaceae
Show/Hide Synonym
AuthorL.
DistributionThroughout the mountains and Piedmont; sparingly into the western Coastal Plain, and very rarely toward the coast. Absent from the far eastern counties north and south of Albemarle and Pamlico sounds, and perhaps a handful of other Coastal Plain counties as well.

This is a widespread Eastern US species, ranging barely into far eastern Canada, and south to the FL panhandle and eastern OK. It is scarce on the South Atlantic Coastal Plain.
AbundanceVery common to locally abundant in the mountains and foothills. Common in the western and central Piedmont, but only infrequent to fairly common (at least locally) in the eastern Piedmont. Rare to very uncommon in the far western Coastal Plain, and very rare in the central and eastern counties.
HabitatThis is a species of cool, moist, and generally rocky slopes. Favored sites include hardwood ravines, cove forests, rocky streamsides, shaded bluffs, and rocky seepages.
See also Habitat Account for General Mesic Hardwood Forests
PhenologyBlooms and fruits from May to July.
IdentificationThis is a familiar deciduous medium-sized shrub growing to an average height of 5-6’ tall. It has opposite leaves, and the leaves are rather large and with long petioles up to 1” long. The leaves are ovate with an acuminate tip, serrate on the margins, and reach 4-5” long (without the petiole). Unlike similar Hydrangea species, the leaf underside is green (though lighter than the dark green upperside). It contains the familiar “hydrangea” inflorescence – a number of broad clusters of medium-sized white flowers but with scattered larger sterile flowers around the outer edge. Though there are a few other plants with such large ovate leaves, such as Canada Horsebalm (Collinsonia canadensis), these have alternate leaves.
Taxonomic CommentsThere are no issues with the species, but several other Hydrangea taxa were formerly included within H. arborescens. RAB (1968) and many others included the current Hydrangea cinerea as H. arboresecens ssp. discolor, and the current H. radiata as H. arborescens ssp. radiata. Most recent treatments have these taxa as separate species.

Other Common Name(s)Wild Hydrangea, Sevenbark. Wild Hydrangea was probably more in use when the other taxa were still included within this species.
State RankS5
Global RankG5
State Status
US Status
County Map - click on a county to view source of record.
Select a source
AllHerbaria
Individual
Website
Select an occurrence type
AllCollection_naturalSight_natural