Flora of North America species comparison

ascending or erect, green or striped with pink or red, branched, (7–)15–90 cm.

usually prostrate to erect, sometimes scandent, not scapose, rarely with recurved spines (some species of Persicaria), glabrous or pubescent, sometimes glandular;

nodes usually swollen;

branches free (adnate to stems distal to nodes and appearing to arise internodally in Polygonella);

tendrils absent (except in Antigonon and Brunnichia).

ocrea brownish hyaline, loose, funnelform, 2–8 mm, margins truncate, eciliate, glabrous or puberulent proximally;

petiole 1.5–6(–9) cm, usually puberulent adaxially;

blade palmately veined with 7–9 primary basal veins, hastate-triangular, sagittate-triangular, or cordate, 2.5–8 × 2–8 cm, base truncate or cordate to sagittate, margins ciliolate, apex acute to acuminate.

deciduous (persistent in Coccoloba and sometimes more than 1 year in Antigonon and Polygonella), basal or basal and cauline, rarely cauline only, mostly alternate;

ocrea present, persistent or deciduous, cylindric to funnelform, chartaceous, membranous, coriaceous, or, rarely, foliaceous or partly so;

petiole present or absent, rarely articulate basally (Fagopyrum, Fallopia, Polygonella, Polygonum), rarely with extrafloral nectaries (Fallopia, Muehlenbeckia);

blade simple with entire margins, rarely undulate or lobed.

terminal and axillary, paniclelike, 1–4 cm, usually crowded at stem apices;

peduncle 0.5–4 cm, puberulent in lines.

terminal or terminal and axillary, spikelike, racemelike, paniclelike, cymelike, or, rarely, capitate, comprising simple or branched clusters of compound inflorescences;

bracts absent;

peduncle spreading to erect, sometimes absent;

clusters of flowers subtended by connate bracteoles forming persistent membranous tube (ocreola), awnless.

ascending or recurved, 2.5–4 mm.

chasmogamous, heterostylous [homostylous];

perianths creamy white to pale pink;

tepals elliptic to obovate, (2.5–)3–5 mm, margins entire, apex obtuse to acute;

stamens ca. 1/2 as long as or slightly longer than perianth;

styles 1.5–2 mm or 0.5–1 mm;

stigmas purplish.

usually bisexual, sometimes bisexual and unisexual on same plant, rarely unisexual only, 1–20+ per ocreate fascicle, often with stipelike base distal to articulation;

perianth often accrescent in fruit, often greenish, white, pink, yellow, red, or purple, usually unwinged and unkeeled (winged or, sometimes, keeled in Fallopia, rarely keeled in Polygonum), campanulate or urceolate, sometimes membranous, indurate, or fleshy in fruit, rarely developing raised tubercles proximally (Rumex), glabrous or pubescent, sometimes glandular or glandular-punctate;

tepals 2–6, usually in 2 whorls, distinct or connate proximally and forming tube, petaloid or sepaloid, monomorphic or dimorphic;

nectary a disk at base of ovary or glands associated with bases of filaments;

stamens usually (1–)6–9, staminodes rarely present;

filaments distinct, or connate basally and sometimes forming staminal tube, free or adnate to perianth tube;

pistils (2–)3(–4)-carpellate;

ovary 1-locular (sometimes with vestigial partitions proximally);

ovule 1, orthotropous or, rarely, anatropous, placentation basal or free-central;

styles 1–3, erect to spreading or recurved, distinct or connate proximally;

stigmas peltate, capitate, fimbriate, or penicillate.

uniformly light brown or streaked with dark brown or black, sharply 3-gonous, 4–6 × 4–6 mm, faces smooth, angles prominent, unwinged or essentially so, smooth or occasionally with blunt tooth in proximal 1/3.

yellowish, brown, red, or black, homocarpic (sometimes heterocarpic in Polygonum), winged or unwinged, usually 2–3-gonous, sometimes discoid, biconvex, or spheroidal, rarely 4-gonous.

embryo usually straight or curved, rarely folded.

= 16 (China).