Stems to 1+ m, commonly with short, leafy axillary branches, minutely puberulent; lvs narrowly oblong or lance-oblong, entire or with a few low callous teeth, finely hairy on the veins beneath, the main ones 2-4 cm, ca a fourth as wide; lateral veins 3-4 pairs, obscure; heads as in no. 3 [Pycnanthemum setosum Nutt.], but the cal 6-10 mm, its lower teeth 2.5-5 mm; 2n=36. Dry woods and barrens, chiefly in sandy soil on the coastal plain; se. Va. to Fla. (P. hyssopifolium)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.