Vascular Plants of North Carolina
Account for Mountain Bush-honeysuckle - Diervilla rivularis   Gattinger
Members of Diervilla with account distribution info or public map:
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Section 6 » Order Dipsacales » Family Diervillaceae
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DistributionOccurs at rather high elevations in the Mountains, known so far only from Mitchell and Yancey counties.

This is a strict southern Appalachian endemic species, ranging north just to eastern TN and western NC, and south to northwestern GA and northern AL. In fact, it has been found in as many counties in AL as in any of the other three states (NC, TN, GA) in its range.
AbundanceVery rare, known from just a handful of sites (one historical) in the state. This is a State Threatened species.
HabitatThis species occurs along rocky stream banks, bluffs, and cliffs, often where shaded or cool – mostly not in as exposed or as dry sites as Diervilla lonicera. Along streams, seems to favor areas with some amount of scour.
PhenologyBlooms from June to August, and fruits from August to October.
IdentificationThis deciduous shrub has a similar growth pattern to the other two Diervilla species, growing only to 2-3 feet tall with widely spreading stems. The narrowly ovate to lanceolate opposite leaves, with serrated margins, are sessile and grow to 4 inches long, but the leaves have essentially no petioles (i.e., are sessile), such that the leaves basically come directly off the stem. It has light yellow flowers in clusters in axils of the outer leaves or at branch tips, as do the others in the genus. However, this species is separated from the much more widespread D. sessilifolia by it quite pubescent leaves and twigs, as well as the pedicels and bracts of the flowers.
Taxonomic CommentsRAB (1968) and a few other references had this taxon as a variety of D. sessilifolia, as D. sessilifolia var. rivularis. Most references, especially recent ones, however, give full species status to this taxon.

Weakley (2020) splits out the family Diervillaceae from Caprifoliaceae, but provides no taxonomic basis for this move. We will await further developments.
Other Common Name(s)Hairy Bush-honeysuckle, Hairy Southern Bush-honeysuckle, Georgia Bush-honeysuckle, Riverbank Bush-honeysuckle. Hairy Bush-honeysuckle would be the best name, and certainly would better describe the species, as all three bush-honeysuckles are found primarily in mountains.
State RankS1
Global RankG3
State StatusT
US Status
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B.A. SorriePhoto taken 2002, Little River Canyon, AL. Photo_non_NCPhoto_non_NC

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