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halberd-leaf smartweed, halberd-leaf tearthumb, renouée à feuilles d'arum

common knotweed, curltop knotweed, curltop ladysthumb, curlytop knotweed, dock-leaf smartweed, pale smartweed, renouée à feuilles de patience, willow weed

Habit Plants annual, 2–15 dm; roots also often arising from proximal nodes. Plants annual, (0.5–)1–10 dm; roots also sometimes arising from proximal nodes; rhizomes and stolons absent.
Stems

scandent, ribbed, glabrous;

prickles 0.5–1 mm.

ascending to erect, simple or branched, scarcely ribbed, glabrous or, rarely, appressed-pubescent distally, sometimes glandular-punctate or stipitate-glandular distally.

Leaves

ocrea tan or brownish, cylindric, 8–15 mm, chartaceous, base inflated or not, with prickles, margins oblique, ciliate with bristles 0.5–2.5 mm, surface glabrous or appressed- to spreading-pubescent;

petiole 1–7 cm;

blade broadly hastate to hastate-cordate or triangular, (2–)6.5–13(–18) × (1–)6–11(–16) cm, base truncate to truncate-cordate, margins broadly hastate with lobes divergent, ciliate, sometimes also retrorsely prickly, apex acuminate, faces appressed-pubescent or, rarely, glabrous adaxially, stellate-pubescent or, rarely, glabrous abaxially, major veins often bearing prickles.

ocrea brownish, cylindric, 4–24(–35) mm, chartaceous, base inflated, margins truncate, eciliate or ciliate with bristles to 1 mm, surface glabrous, rarely strigose, eglandular;

petiole 0.1–1.6 cm, usually strigose, sometimes glabrous;

blade sometimes with dark triangular or lunate blotch adaxially, narrowly to broadly lanceolate, 4–12(–22) × (0.3–)0.5–4(–6) cm, base tapering to cuneate, margins antrorsely scabrous, apex acuminate, faces strigose on main veins, glabrous or tomentose abaxially, glandular-punctate abaxially.

Inflorescences

capitate or paniclelike, uninterrupted, 5–12 × 3–8 mm;

peduncle 10–80 mm, retrorsely prickly proximally, stellate-pubescent and stipitate-glandular distally, glands red or pink;

ocreolae usually overlapping, sometimes not overlapping proximally, margins eciliate or ciliate with bristles to 0.5 mm.

mostly terminal, sometimes also axillary, mostly arching or nodding, usually uninterrupted, 30–80 × 5–12 mm;

peduncle 2–25 mm, often stipitate-glandular;

ocreolae usually overlapping, margins eciliate or ciliate with bristles to 0.4 mm.

Pedicels

mostly ascending, 2–3 mm.

ascending, 0.5–2.3 mm.

Flowers

2–4 per ocreate fascicle;

perianth pink or red, often whitish green proximally, glabrous, accrescent, not becoming blue and fleshy in fruit;

tepals 4, connate 1/3–1/2 their length, broadly elliptic, 5–6 mm, apex acute to obtuse;

stamens (6–)8, filaments distinct, free;

anthers pink, elliptic;

styles 2, distinct.

4–14 per ocreate fascicle, homostylous;

perianth greenish white to pink, glabrous, not glandular-punctate or glandular-punctate with punctae mostly on tubes and inner tepals, scarcely accrescent;

tepals 4(–5), connate ca. 1/4–1/3 their length, obovate to elliptic, 2.5–3 mm, veins prominent, those of 2 or 3 outer tepals prominently bifurcate distally, anchor-shaped, margins entire, apex obtuse to rounded;

stamens 5–6, included;

anthers pink or red, elliptic;

styles 2(–3), connate at bases.

Achenes

included, dark brown to black, biconvex, 3.5–6 × 3–4 mm, shiny, smooth.

included or apex exserted, brown to black, discoid or, rarely, 3-gonous, 1.5–3.2 × 1.6–3 mm, shiny or dull, smooth.

2n

= 22.

Persicaria arifolia

Persicaria lapathifolia

Phenology Flowering Jul–Oct. Flowering (Apr-)Jul–Nov.
Habitat Shaded swamps, ponds, tidal marshes along rivers, wet ravines in forests Moist places, roadsides, floodplains, waste places, cultivated fields
Elevation 0-600 m (0-2000 ft) 0-1500(-1800) m (0-4900(-5900) ft)
Distribution
from FNA
CT; DC; DE; GA; IL; IN; KY; LA; MA; MD; ME; MI; MN; MO; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WA; WI; WV; NB; NS; ON; PE; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; SPM; Mexico; South America; Africa; Greenland; Asia; Europe; Pacific Islands (New Zealand)
[WildflowerSearch map]
[BONAP county map]
Discussion

Persicaria lapathifolia is a morphologically variable complex with more than two-dozen infraspecific taxa described in the New World and Old World. An allozyme study by L. L. Consaul et al. (1991) did not support recognition of elements often referred to Polygonum lapathifolium var. salicifolium or P. scabrum, which are synonymized here. Yang J. and Wang J. W. (1991) reached a similar conclusion regarding var. salicifolium and P. nodosum based on their morphometric analysis.

The Keres, Navajo, and Potawatomi prepared medicinal infusions with Persicaria lapathifolia, and the Zuni used decoctions made from the plants as cathartic and emetic drugs (D. E. Moerman 1998).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 577. FNA vol. 5, p. 589.
Parent taxa Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria
Sibling taxa
P. amphibia, P. bicornis, P. bungeana, P. capitata, P. careyi, P. chinensis, P. glabra, P. hirsuta, P. hydropiper, P. hydropiperoides, P. lapathifolia, P. longiseta, P. maculosa, P. meisneriana, P. minor, P. nepalensis, P. orientalis, P. pensylvanica, P. perfoliata, P. punctata, P. robustior, P. sagittata, P. setacea, P. virginiana, P. wallichii
P. amphibia, P. arifolia, P. bicornis, P. bungeana, P. capitata, P. careyi, P. chinensis, P. glabra, P. hirsuta, P. hydropiper, P. hydropiperoides, P. longiseta, P. maculosa, P. meisneriana, P. minor, P. nepalensis, P. orientalis, P. pensylvanica, P. perfoliata, P. punctata, P. robustior, P. sagittata, P. setacea, P. virginiana, P. wallichii
Synonyms Polygonum arifolium, Polygonum arifolium var. lentiforme, Polygonum arifolium var. pubescens, Polygonum sagittatum var. pubescens, Tracaulon arifolium, Truellum arifolium Polygonum lapathifolium, Polygonum incarnatum, Polygonum lapathifolium var. ovatum, Polygonum lapathifolium var. salicifolium, Polygonum linicola, Polygonum nodosum, Polygonum pensylvanicum var. oneillii, Polygonum scabrum, Polygonum tomentosum
Name authority (Linnaeus) Haraldson: Acta Univ. Upsal., Symb. Bot. Upsal. 22: 72. (1978) (Linnaeus) Gray: Nat. Arr. Brit. Pl. 2: 270. (1822)
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