Persicaria punctata |
Persicaria perfoliata |
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dotted knotweed, dotted smartweed, renouée ponctuée, water smartweed |
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 or perennial, 1.5–12 dm; roots also often arising from proximal nodes; rhizomes often present. | Plants annual, 10–20(–70) dm; roots not also arising from proximal nodes. |
Stems | ascending to erect, branched, without noticeable ribs, glabrous, glandular-punctate. |
scandent, ribbed, glabrous, often glaucous; prickles 0.5–1 mm. |
Leaves | ocrea brown, cylindric, (4–)9–18 mm, chartaceous, base inflated, margins truncate, ciliate with bristles 2–11 mm, surface glabrous or strigose, glandular-punctate; petiole 0.1–1 cm, glandular-punctate, leaves sometimes sessile; blade without dark triangular or lunate blotch adaxially, lanceolate to lanceolate-ovate or subrhombic, 4–10(–15) × 0.6–2.4 cm, base tapered or cuneate, margins antrorsely strigose, apex acute to acuminate, faces glabrous or scabrous along midveins, glandular-punctate. |
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 | mostly terminal, sometimes also axillary, erect, interrupted, 50–200 × 4–8 mm; peduncle 30–60 mm, glabrous, glandular-punctate; ocreolae mostly not overlapping, margins mostly ciliate with bristles to 2 mm. |
capitate or spikelike, uninterrupted, 5–12 × 5–10 mm; peduncle 10–50 mm, retrorsely prickly; ocreolae overlapping, margins eciliate. |
Pedicels | ascending, 1–4 mm. |
mostly ascending, 1–3 mm. |
Flowers | 2–6 per ocreate fascicle, homostylous; perianth greenish proximally, white distally, rarely tinged pink, glandular-punctate with punctae ± uniformly distributed, scarcely accrescent; tepals 5, connate ca. 1/3 their length, obovate, 3–3.5 mm, veins prominent or not, not anchor-shaped, margins entire, apex obtuse to rounded; stamens 6–8, included; anthers pink or red, elliptic to ovate; styles 2–3, connate proximally. |
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 apex exserted, brownish black, usually 3-gonous, rarely biconvex, (1.8–)2.2–3.2 × 1.5–2.2 mm, shiny, smooth. |
included, black or reddish black, spheroidal, 3–3.5 × 3–3.5 mm, shiny, smooth. |
2n | = 44. |
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Persicaria punctata |
Persicaria perfoliata |
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Phenology | Flowering Jun–Nov. | Flowering Jun–Oct. |
Habitat | Shallow water, shores, marshes, floodplain forests | Thickets, streams banks, pastures, forest edges, roadsides, railroad embankments, other moist, disturbed sites |
Elevation | 0-1500 m (0-4900 ft) | 0-300 m (0-1000 ft) |
Distribution |
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; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; VA; VT; WA; WI; WV; WY; HI; BC; MB; NB; NS; ON; PE; QC; SK; Mexico; West Indies (Puerto Rico); Central America (Guatemala); South America (Brazil)
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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 | N. C. Fassett (1949) proposed a complicated classification for Persicaria punctata with 12 varieties in North America and South America. He also identified numerous specimens that he considered to be morphologically intermediate between various varieties. M. Dalci (1972) documented a wide range of phenotypic and genotypic variation throughout the range of P. punctata and extensive overlap in many of the features used by Fassett to distinguish varieties. Consequently, recognition of varieties does not seem warranted. Persicaria punctata and its close relatives P. robustior and P. glabra are unique among native North American smartweeds in possessing complex glands called valvate chambers in their epidermises. Persicaria punctata is confused most frequently with P. hydropiper; the achenes are diagnostic. The Chippewa, Houma, and Iroquois prepared decoctions from leaves, flowers, and roots for use as analgesics as well as gastrointestinal, orthopedic, and psychological aids (D. E. Moerman 1998). (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. 586. | FNA vol. 5, p. 577. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon |
Sibling taxa | ||
Synonyms | Polygonum punctatum, Polygonum acre var. leptostachyum, Polygonum punctatum var. confertiflorum, Polygonum punctatum var. ellipticum, Polygonum punctatum var. leptostachyum, Polygonum punctatum var. parviflorum, Polygonum punctatum var. parvum | Polygonum arifolium var. perfoliatum, Polygonum perfoliatum |
Name authority | (Elliott) Small: Fl. S.E. U.S., 379. (1903) | (Linnaeus) H. Gross: Beih. Bot. Centralbl. 37(2): 113. (1919) |
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