Perennial, somewhat fleshy shrub or coarse herb 0.5-3.5 m, puberulent or strigose at least above; lvs generally all opposite except the reduced upper ones, the main ones 4-10 cm, evidently short-petiolate; invol 2-4 mm, of 4-5(6) equal bracts; pistillate fls 4-5(6), with tubular cor 1 mm tending to persist on the copiously resin-dotted achene; 2n=34. Marshes and other moist places along the seashore; N.S. and Mass. to Fla. and Tex. Our plants are mostly var. oraria (Bartlett) Fernald & Griscom, with lvs less than 4 times as long as wide, to 10 נ4 cm, and with 8-17 teeth to a side. In Va. this passes into the more southern var. frutescens, with smaller, narrower lvs (4-7נ0.7-1.5 cm, 4-8 times as long as wide) with to ca 8 teeth to a side (or subentire).
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.