Persicaria lapathifolia |
Persicaria bungeana |
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common knotweed, curltop knotweed, curltop ladysthumb, curlytop knotweed, dock-leaf smartweed, pale smartweed, renouée à feuilles de patience, willow weed |
prickly smartweed |
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Habit | Plants annual, (0.5–)1–10 dm; roots also sometimes arising from proximal nodes; rhizomes and stolons absent. | Plants annual, 3–8 dm; roots not also arising from proximal nodes. |
Stems | ascending to erect, simple or branched, scarcely ribbed, glabrous or, rarely, appressed-pubescent distally, sometimes glandular-punctate or stipitate-glandular distally. |
ascending to erect, ribbed or obscurely so, glabrous or glandular-pubescent distally; prickles 1–1.5 mm. |
Leaves | 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. |
ocrea brownish, cylindric, 8–14 mm, chartaceous, base inflated or not, without prickles, margins truncate, ciliate with bristles 2–4 mm, surface with appressed bristles along veins; petiole 0.5–1.5 cm; blade lanceolate to narrowly elliptic, 5–12.5 × 1.5–3.5 cm, base acute, margins entire, antrorsely ciliate, apex acute acuminate, rarely obtuse, faces glabrous or pubescent and, usually, with antrorse prickles along midvein abaxially and adaxially. |
Inflorescences | 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. |
racemelike, uninterrupted or interrupted proximally, 20–45 × 5–10 mm; peduncle 20–40 mm, usually stipitate-glandular at least proximally; ocreolae usually overlapping, sometimes not overlapping proximally, margins eciliate. |
Pedicels | ascending, 0.5–2.3 mm. |
mostly ascending, 2–3 mm. |
Flowers | 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. |
2–4 per ocreate fascicle; perianth pale green, often tinged red, glabrous, accrescent, not becoming blue and fleshy in fruit; tepals 5, connate 1/4–1/3 their length, petaloid, elliptic to broadly elliptic, 3–4 mm, apex obtuse; stamens 8, filaments distinct, free; anthers pink, ovate; styles 2, connate to middle. |
Achenes | included or apex exserted, brown to black, discoid or, rarely, 3-gonous, 1.5–3.2 × 1.6–3 mm, shiny or dull, smooth. |
included, black, biconvex, 2.5–3 × 2.3–2.8 mm, dull, rugose. |
2n | = 22. |
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Persicaria lapathifolia |
Persicaria bungeana |
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Phenology | Flowering (Apr-)Jul–Nov. | Flowering Jul–Sep. |
Habitat | Moist places, roadsides, floodplains, waste places, cultivated fields | Cultivated fields |
Elevation | 0-1500(-1800) m (0-4900(-5900) ft) | 300-400 m (1000-1300 ft) |
Distribution |
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)
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IA; IL; MN; e Asia (n China, Japan, Korea, Manchuria) [Introduced in North America] |
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.) |
Persicaria bungeana is a weed of soybean fields (R. N. Andersen et al. 1985). It is not known how or when it was introduced into the midwestern United States. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 589. | FNA vol. 5, p. 578. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon |
Sibling taxa | ||
Synonyms | Polygonum lapathifolium, Polygonum incarnatum, Polygonum lapathifolium var. ovatum, Polygonum lapathifolium var. salicifolium, Polygonum linicola, Polygonum nodosum, Polygonum pensylvanicum var. oneillii, Polygonum scabrum, Polygonum tomentosum | Polygonum bungeanum |
Name authority | (Linnaeus) Gray: Nat. Arr. Brit. Pl. 2: 270. (1822) | (Turczaninow) Nakai: in T. Mori, Enum. Pl. Corea, 131. (1922) |
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