Flora of North America species comparison

prostrate to ascending or erect, simple or branched, ribbed, glabrous or strigose to hirsute.

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 tan to dark brown, cylindric or flared distally, 5–50 mm, chartaceous or, sometimes, foliaceous distally, base inflated, margins truncate to oblique, glabrous or ciliate with hairs 0.5–4.5 mm, surface glabrous or appressed-pubescent to hirsute, not glandular-punctate;

petiole 0.1–3(–7) cm, glabrous or appressed-pubescent to hirsute, leaves sometimes sessile;

blade without dark triangular or lunate blotch adaxially, ovate-lanceolate to elliptic or oblong-lanceolate, 2–15(–23) × 1–6(–8) cm, base usually tapered to acute or rounded, rarely cordate, margins antrorsely scabrous, apex acute to acuminate, faces glabrous or sparingly strigose, midveins glabrous or strigose, not glandular-punctate.

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, ascending to erect, uninterrupted or interrupted proximally, 10–150 × 8–20 mm;

peduncle 10–50 mm, glabrous or strigose to hirsute, often stipitate-glandular;

ocreolae overlapping except sometimes proximal ones, margins ciliate with bristles to 1 mm.

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, 0.5–1.5 mm.

bisexual or functionally unisexual, some plants having only staminate flowers, others with only pistillate flowers, 1–3(–4) per ocreate fascicle, heterostylous;

perianth roseate to red, glabrous, not glandular-punctate, slightly accrescent;

tepals 5, connate ca. 1/3 their lengths, obovate to elliptic, 4–6 mm, veins prominent, not anchor-shaped, margins entire, apex rounded to acute;

stamens 5, included or exserted;

anthers pink or red, elliptic;

styles 2, included or exserted, connate 1/2–2/3 their length.

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.

included, dark brown, biconvex, (2–)2.2–3 × (1.5–)1.8–2.6 mm, shiny or dull, smooth or minutely granular.

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.

= 66, 132.