Pycnanthemum verticillatum - (image 1 of 6)
Taxonomy
Family: Lamiaceae
Habitat
Upland woods and thickets, clearings.
Associates
Distribution
VT to NC, west to MI, IA, western KS, and western OK; var. verticillatum is more eastern, ranging west to MI, OH, and eastern KY; var. pilosum (syn. P. pilosum) is more western, ranging east to OH and southern MI.
Morphology
Herbaceous perennial; stems to 1.5 m, branching above and usually with some short axillary branches, more or less hairy, especially above; leaves narrowly lanceolate, acute to acuminate, mostly with a few low teeth, the main ones 3-5 cm long and 8-12(-15) mm wide, with 4-7 pairs of lateral veins; heads numerous, dense, 8-15(-20) mm wide; outer foliaceous bracts velvety above; inner bracts ciliolate, with a conspicuous midvein; calyx lobes narrowly deltoid, 0.5-1.0 mm.
Notes
Flowers mid-summer
Wetland indicator: FAC
The plants shown here are the eastern var. verticillatum with leaves that are hairy mainly along the veins beneath. The more western var. pilosum is more hairy, with the stem conspicuously spreading-pilose and the lower leaf surfaces evenly spreading-hairy and the calyx more or less shaggy. Might be confused with P. virginianum which has the pubescence of the stem confined mainly to the angles; P. verticillatum is evenly pubescent on the faces as well as the angles. Pycnanthemum torrei is most like P. verticillatum but has softer and less veiny leaves, calyx teeth longer and sharper (1-1.5 mm), and involucral bracts that are lanceolate and acuminate to aristate.
References
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY.
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Michael Hough © 2018 |