Persicaria sagittata |
Persicaria perfoliata |
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arrow-leaf knotweed, arrow-leaf tearthumb, arrow-vine, renouée sagittée |
Asiatic smartweed, Asiatic tearthumb, devil's-tail, devil's-tail or giant climbing tearthumb, giant climbing tearthumb, mile a minute, mile-a-minute weed |
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Habit | Plants annual, 3–20 dm; roots also often arising from proximal nodes. | Plants annual, 10–20(–70) dm; roots not also arising from proximal nodes. |
Stems | scandent, ribbed, glabrous; prickles 1–1.5 mm. |
scandent, ribbed, glabrous, often glaucous; prickles 0.5–1 mm. |
Leaves | ocrea brownish, cylindric, (3–)5–13 mm, chartaceous, base inflated or not, without prickles, margins oblique, glabrous or ciliate at tip with bristles 0.2–1 mm, surface glabrous; petiole 0.5–4 cm; blade broadly lanceolate to oblong, 2–8.5 × 1–3 cm, base sagittate to cordate, margins entire, ciliate or eciliate, apex obtuse to acute, faces glabrous or densely appressed-pubescent, usually with retrorse prickles along midvein abaxially. |
ocrea green, plane to broadly funnelform, 9–14 mm, at least some foliaceous, base inflated or not, without prickles, margins oblique, eciliate, surface glabrous, glaucous; petiole 4.5–8 cm; blade triangular, 4–7 × 4.5–9 cm, base truncate to cordate, usually peltate, margins entire, sparsely retrorsely prickly, apex acuminate, faces glabrous, usually glaucous abaxially. |
Inflorescences | capitate or paniclelike, uninterrupted, 5–15 × 4–10 mm; peduncle 10–80 mm, usually glabrous, sometimes with retrorse prickles proximally; ocreolae overlapping, margins eciliate. |
capitate or spikelike, uninterrupted, 5–12 × 5–10 mm; peduncle 10–50 mm, retrorsely prickly; ocreolae overlapping, margins eciliate. |
Pedicels | mostly ascending, 1–1.5 mm. |
mostly ascending, 1–3 mm. |
Flowers | 2–3 per ocreate fascicle; perianth white or greenish white, often tinged pink or red, sometimes entirely pink, glabrous, accrescent, not becoming blue and fleshy in fruit; tepals 5, connate 1/3–1/2 their length, broadly elliptic, 3–5 mm, apex obtuse; stamens 8, filaments distinct, free; anthers pink, ovate; styles 3, connate to middle. |
1–3 per ocreate fascicle; perianth greenish white, glabrous, accrescent, becoming fleshy and blue in fruit; tepals 5, connate to ca. 1/3 their length, broadly elliptic, 2–3.5 mm, apex acute to obtuse; stamens (6–)8, filaments distinct, free; anthers pinkish, ovate; styles 3, connate proximally. |
Achenes | included or styles exserted, light or dark brown to black, 3-gonous, 2.5–4 × 1.8–2.5 mm, dull to shiny, smooth to minutely punctate. |
included, black or reddish black, spheroidal, 3–3.5 × 3–3.5 mm, shiny, smooth. |
2n | = 40. |
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Persicaria sagittata |
Persicaria perfoliata |
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Phenology | Flowering Jun–Oct. | Flowering Jun–Oct. |
Habitat | Moist shaded sites, meadows, pastures, fens, swamps, shorelines of ponds and streams | Thickets, streams banks, pastures, forest edges, roadsides, railroad embankments, other moist, disturbed sites |
Elevation | 0-1000 m (0-3300 ft) | 0-300 m (0-1000 ft) |
Distribution |
AL; AR; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; MB; NB; NF; NS; ON; PE; QC; e Asia
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CT; DC; DE; MD; MS; NJ; NY; OH; OR; PA; RI; VA; WV; Asia [Introduced in North America]
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Discussion | Persicaria sagittata is an extremely variable species. Achene and leaf characters have been used by some authors to separate North American and Asian populations, but these characters show weak geographic variation (C. W. Park 1988). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Persicaria perfoliata is an aggressive, fast-growing pest in its native range and in North America. At least some introductions appear to be through the nursery trade (J. C. Hickman and C. S. Hickman 1978; R. E. Riefener 1982). It was collected once in 1954 in British Columbia, but that population did not persist. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 577. | FNA vol. 5, p. 577. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon |
Sibling taxa | ||
Synonyms | Polygonum sagittatum, Polygonum sagittatum var. gracilentum, Tracaulon sagittatum, Truellum sagittatum | Polygonum arifolium var. perfoliatum, Polygonum perfoliatum |
Name authority | (Linnaeus) H. Gross: Beih. Bot. Centralbl. 37(2): 113. (1919) | (Linnaeus) H. Gross: Beih. Bot. Centralbl. 37(2): 113. (1919) |
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