Persicaria wallichii |
Persicaria perfoliata |
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garden knotweed, garden smartweed, Himalayan knotweed, Kashmir plume |
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, 10–20(–70) dm; roots not also arising from proximal nodes. | |
Stems | scandent, ribbed, glabrous, often glaucous; prickles 0.5–1 mm. |
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Leaves | 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. |
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Inflorescences | capitate or spikelike, uninterrupted, 5–12 × 5–10 mm; peduncle 10–50 mm, retrorsely prickly; ocreolae overlapping, margins eciliate. |
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Pedicels | mostly ascending, 1–3 mm. |
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Flowers | 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. |
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Achenes | included, black or reddish black, spheroidal, 3–3.5 × 3–3.5 mm, shiny, smooth. |
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Persicaria wallichii |
Persicaria perfoliata |
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Phenology | Flowering Jun–Oct. | |
Habitat | Thickets, streams banks, pastures, forest edges, roadsides, railroad embankments, other moist, disturbed sites | |
Elevation | 0-300 m (0-1000 ft) | |
Distribution |
CA; MA; OR; BC; 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 | Varieties 2 (1 in the flora). Persicaria wallichii is an ornamental that escapes infrequently in the flora area. A population in Nova Scotia apparently was ephemeral. Plants with leaf blades sparsely to densely pubescent abaxially and pedicels glabrous are var. wallichii, to which naturalized North American plants appear to be referable. Plants with leaf blades brownish-tomentose abaxially and pedicels usually pubescent are var. tomentosa S. P. Hong, which may be in cultivation in North America. (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. 581. | FNA vol. 5, p. 577. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Rubrivena | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Polygonum polystachyum, Aconogonon polystachyum, Pleuropteropyrum polystachyum, Reynoutria polystachya, Rubrivena polystachya | Polygonum arifolium var. perfoliatum, Polygonum perfoliatum |
Name authority | Greuter & Burdet: Willdenowia 19: 41. (1989) | (Linnaeus) H. Gross: Beih. Bot. Centralbl. 37(2): 113. (1919) |
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