Vascular Plants of North Carolina
Account for Northeastern Bindweed - Convolvulus americanus   (Sims) Greene
Members of Convolvulus with account distribution info or public map:
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Section 6 » Family Convolvulaceae
Author(Sims) Greene
DistributionThe former Calystegia sepium from RAB (1968) has now been split out into several species, not to mention all now in the genus Convolvulus. Thus, many specimens labelled as C. sepium have probably not been sorted or moved into the new species. For now, the website editors have mapped records to scattered counties in the Coastal Plain, mainly in the northern portions, plus an isolated record of the northern mountains (Alleghany County).

Weakley (2018) shows the range in the Southeastern states only ranging south to the NC Coastal Plain, found northward. His map shows no record for the Piedmont or mountains of NC or VA, and thus the website editors have assigned a Provenance Uncertain to the mountain record.
AbundanceVery poorly known, but Weakley's (2018) map says "rare" for the NC Coastal Plain. The website editors have given a State Rank of S2? and suggest it should be on the Watch List until more is known about it.
HabitatWeakley (2018) simply says "Openings, woodland edges."
PhenologyProbably blooms from May to August, and fruits shortly after flowering.
IdentificationMembers of the former Calystegia sepium (now Convolvulus) complex -- C. americanus, C. fraterniflorus, C. limnophilus, and species 2 -- all are herbaceous vines that range to about 12' long or more, and they are also strongly twining. The large alternate leaves are mostly arrowhead-shaped to triangular, with long tips and heart-shaped or more often squared-off leaf bases. Flowers are mostly in the middle and upper leaf axils and are quite large, funnel-shaped, about 2-3" long and across, either white or pink with yellow deep in the throat. C. fraterniflorus differs from the other three by the "margins of the bracts immediately subtending the flower overlapping > 1/2 their length; bracts inflated at base (saccate), the apex usually obtuse; flowers 1-2 per axil" (Weakley 2018) -- versus "margins of the bracts immediately subtending the flowers overlapping at the base only or not at all; bracts mostly flat (or often keeled), the apex usually acute; flowers 1 per axil" in the others. Of this latter group, only C. limnophilus has white flowers, whereas C. americanus and C. species 2 have pink flowers. These latter two are separated by "Leaves with basal lobes rounded or with a single angle, or if with 2 angles then not spreading; plant glabrous or commonly pubescent to tomentose on stem" (Weakley 2018) for C. americanus -- versus "Leaves with lobes with 2 angles, spreading; plant glabrous" for C. species 2. In summary, this is the only pink-flowered member of the group in the Coastal Plain, as C. fraterniflorus is normally white-flowered.
Taxonomic CommentsSee Distribution.

Other Common Name(s)None?
State Rank[S2?]
Global RankG5
State Status[W7]
US Status
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