Polygonum ramosissimum Michx.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Freely branched, mostly erect or ascending annual 3–10 dm (or reputedly to 20 dm), ± strongly heterophyllous, the rameal lvs abruptly smaller than those of the main stem; lower internodes to 5 cm, the upper progressively shorter; lvs linear to narrowly lance- elliptic, 1–6 cm × 2–5(–10) mm, obtuse or acute, flat; fls 1–3 and exsert from the upper ocreae on pedicels 2–3.5 mm, forming racemes to 15 cm, mature perianth 3–4 mm, deeply cleft, the 3 outer tep cucullate and notably exceeding the inner 2, especially in fr; achenes smooth and ± shiny, the earlier ones blackish, 2–3.5 mm, thickly ovoid, and included in the perianth, but some of the later ones often paler, narrowly ovoid, 4–5 mm, and exsert; 2n=60. Unstable, usually moist, sometimes saline habitats, sometimes in coastal marshes, but also widespread inland; Me. and Que. to Wash., s. to Del., Ill., and N.M. (P. atlanticum; P. exsertum; P. triangulum)