Herbs, perennial, not rhizomatous, 1-5 m. Stems usually scandent or sprawling, rarely erect, freely branched, herbaceous, pilose-hispid or, rarely, subglabrous, not glaucous. Leaves: ocrea usually deciduous, light brown, cylindric, 3-4 mm, margins oblique, base fringed with reflexed hairs and slender bristles, face glabrous or puberulent; petiole 1-6 cm, retrorsely pubescent; blade cordate-ovate, cordate-hastate, or cordate-sagittate, 2-6(-12) × 2-5(-10) cm, base cordate, margins wavy, often reddish-ciliate, apex acute to acuminate, abaxial face pilose-hispid, not minutely dotted, not glaucous, adaxial face glabrous. Inflorescences terminal and axillary, erect or spreading, paniclelike, 4-10(-15) cm, axes reddish-pilose; peduncle 1-12 cm, retrorsely pubescent. Pedicels ascending or spreading, articulated near middle or distally, 3-4 mm, glabrous or puberulent. Flowers bisexual, 4-7 per ocreate fascicle; perianth nonaccrescent, greenish white to white, 1.5-2 mm including stipelike base, glabrous; tepals elliptic, apex obtuse to acute, outer 3 obscurely keeled; stamens 6-8; filaments flattened proximally, pubescent proximally; styles connate basally; stigmas capitate. Achenes included or exserted, brownish black to black, 3-4 × 1.8-2.4 mm, shiny, smooth; fruiting perianth glabrous, wings absent. 2n = 22. Flowering Jun-Oct. Dry woods, thickets, clearings; 0-900 m; Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask.; Conn., Ga., Ill., Ind., Ky., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis. Á. Löve and D. Löve (1982) reported a chromosome count of 2n = 20 for Fallopia cilinodis. All other counts summarized by J. P. Bailey and C. A. Stace (1992) and counts by M. H. Kim et al. (2000) are 2n = 22. It is not known if the 2n = 20 count is an error.
Twining or trailing to occasionally erect perennial, to 2 m, pubescent to subglabrous; lvs ovate to triangular-ovate with deeply cordate base; ocreae very oblique, reflexed-bristly at base; racemes long-peduncled, mostly branched, 4-10 cm, the small fl-clusters remote; fls white, 1.5-2 mm; achene very glossy, black, closely invested but scarcely surpassed by the perianth, the 3 outer tep rarely narrowly winged; styles separate, divergent; 2n=20, 40. Dry woods and thickets; Nf. and Que. to n. Minn., s. to Pa. and s. Mich., and in the mts. to N.C. (Bilderdykia c.; Tiniaria c.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.