Vascular Plants of North Carolina
Account for Southern Mountain-mint - Pycnanthemum pycnanthemoides   (Leavenworth) Fernald
Members of Pycnanthemum with account distribution info or public map:
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Section 6 » Order Lamiales » Family Lamiaceae
Author(Leavenworth) Fernald
DistributionOccurs throughout the mountains, essentially throughout the Piedmont, and sparingly into the western and central Coastal Plain. Though this species was unfortunately subsumed within P. incanum in RAB (1968), Gleason (1952) listed it as a good species, as do most references. Weakley (2018) and Gleason (1952) give two varieties of it in the state, distinctions of which are beyond the scope of this website. However, it appears that the majority of the county records for P. incanum in RAB (1968) relate to this species.

This is a Mid-Atlantic species, ranging from MD and southern IL, south to western FL and AL.
AbundanceCommon in the mountains; fairly common to frequent in the Piedmont; rare in the Coastal Plain, found east to Martin, Craven, and Jones counties. The NCNHP has the species in its database but has never given a State Rank; the website editors feel that a rank of S5 (common) is appropriate.
HabitatThis species has a wide range of habitats, none specialized. It occurs along wooded borders, old fields, open woods, and meadows, though it is more often found in partial shade.
PhenologyBlooms in July and August, and fruits soon after flowering.
IdentificationThis species is a typical mountain-mint, being about 3' tall, freely branched in the upper portions of the stem, and with numerous pairs of opposite leaves. The leaves tend to be ovate, nearly sessile, toothed along the margin, and about 2-3" long and half as wide. These species have rather flat-topped heads of about 1-2" wide at the ends of each branch, subtended by whitened bracts, with the flowers being very small and often pink (as opposed to white in many other species). There are many such heads in bloom over the plant, often dozens of them. Separation of this species from others is technical and involves closely examining the calyx or the seeds. Use Weakley (2018) or Wofford (1989) to key out the species, as well as the two varieties (to add to your confusion). Somewhat helpful is Gleason's (1952) comment: "Closely resembling P. incanum in habit, foliage, and pubescence, although with a general tendency toward more numerous spreading hairs on the bracts and calyx lobes." He also mentions the difference in flower color, with this species having pink to purple corollas, versus white spotted with purple in P. incanum. As mentioned in Distribution and Abundance, this should be a frequently encountered mountain-mint in the mountains and Piedmont.
Taxonomic CommentsWeakley (2018), Gleason (1952), and some other references list two varieties in NC -- the nominate var. pycnanthemoides (which Weakley shows as common in the mountains and uncommon in the Piedmont) and var. viridifolium (which Weakley shows as uncommon in the mountains and Piedmont, and rare in the Coastal Plain). Populating the county range maps for these varieties on this website is unlikely to be done in the foreseeable future, as few specimens have this level of distinction.

Other Common Name(s)None
State Rank[S5]
Global RankG5
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US Status
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