Vascular Plants of North Carolina
Account for Thinleaf Mountain-mint - Pycnanthemum montanum   Michaux
Members of Lamiaceae:
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Section 6 » Order Lamiales » Family Lamiaceae
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DistributionThis is a species with a fairly small global range, not even reaching VA. Thus, it occurs from Watauga County southward through the rest of the NC mountains. It probably does not quite range into western Piedmont ranges, as records from Polk and a few other counties along the eastern edge of the range are from the Blue Ridge Escarpment.

This is a Southern Appalachian endemic, ranging only from northwestern NC and adjacent TN south to northwestern SC and northern GA. Found only in these four states.
AbundanceFairly common to locally common, north only to Watauga County; presumed absent from Ashe and Alleghany counties.
HabitatThis species grows more in rich forests than many other species in the genus, including growing in full shade. However, it also grows around the margins of balds and granitic domes, as well as along wooded borders.
PhenologyBlooms from June to August, and fruits from September to October.
IdentificationThis species is a typical mountain-mint, being about 3 feet tall, freely branched in the upper portions of the stem, and with numerous pairs of opposite leaves. In this species, the leaves tend to be lanceolate to elliptic, about 4 inches long and about 1.3 inches wide; and instead of rounded at the base to a very short petiole, this species has more cuneate bases tapering into a petiole. These species have rather flat-topped heads of about 1-2 inches wide at the ends of each branch, subtended by bracts, with the flowers being very small and generally white with some purple spots on the lower lip. There are many such heads in bloom over the plant, often dozens of them. This species has quite narrow bracts that are green or at least not hoary white, and they are strongly ciliate on the margins. Most other species in the mountains have bracts that are not hairy along the margins, and they are wider and/or whiter. Look for the narrower and greener bracts, and longer leaves with more taper to the stem to identify this numerous montane species.
Taxonomic CommentsNone

Other Common Name(s)Appalachian Mountain-mint, Single-haired Mountain-mint
State RankS3
Global RankG3G5
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