Subshrubs or shrubs, 50-350 cm. Stems erect. Leaves: petioles 5-10+ mm; blades ovate or elliptic to lanceolate, 30-60(-120+) × 5-30(-40) mm, margins usually toothed, faces closely scabrellous, gland-dotted. Heads in ± racemiform arrays. Peduncles 1-3+ mm. Involucres ± hemispheric, 2-4 mm. Phyllaries: outer 5 distinct, ± herbaceous. Paleae linear to subulate, 2.5-3 mm. Pistillate florets (2-)5; corollas 0.7-1 mm. Functionally staminate florets 3-8(-15+); corollas 2-3 mm. Cypselae 2-3 mm. 2n = 34.
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.