Persicaria wallichii |
Persicaria minor |
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garden knotweed, garden smartweed, Himalayan knotweed, Kashmir plume |
Asian knotweed, petite renouée, pygmy smartweed, small smartweed, small water-pepper |
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Habit | Plants annual, 0.5–3(–4) dm; roots also sometimes at from proximal nodes; rhizomes and stolons absent. | |
Stems | decumbent or ascending, branched proximally, scarcely ribbed, glabrous or scabrous distally. |
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Leaves | ocrea brownish, cylindric, 3–10 mm, chartaceous, base not inflated, margins truncate, ciliate with bristles (0.3–)1–3(–5) mm, surface glabrous or strigose, not glandular-punctate; petiole 0.1–0.2 cm, glabrous or strigose, leaves sometimes sessile; blade without dark triangular or lunate blotch adaxially, linear to linear-lanceolate, (1–)2–7.5(–10) × (0.2–)0.4–1(–2.3) cm, base tapered to cuneate, margins antrorsely scabrous, apex acute to acuminate, faces glabrous or sparingly strigose, especially along midveins, not glandular-punctate. |
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Inflorescences | terminal and axillary, ascending to erect, usually interrupted proximally, uninterrupted distally, 10–50 × 2–4 mm; peduncle (0–)2–25 mm, sometimes absent on axillary inflorescences and flowers thus enclosed in ocreae, glabrous; ocreolae not overlapping proximally, usually overlapping distally, margins ciliate with bristles (0.1–)0.6–2(–2.7) mm. |
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Pedicels | ascending, 0.5–1 mm. |
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Flowers | 1–3(–4) per ocreate fascicle, homostylous; perianth roseate to red, rarely white, glabrous, not glandular-punctate, scarcely accrescent; tepals 5, connate ca. 1/3 their length, obovate to elliptic, 2.5–3 mm, veins not prominent, not anchor-shaped, margins entire, apex obtuse to rounded; stamens 5(–6), included; anthers yellow to pink, elliptic; styles 2(–3), connate at bases. |
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Achenes | included, brownish black to black, biconvex or, rarely, 3-gonous, (1.5–)1.8–2.3(– 2.7) × (1.1–)1.3–1.5(–1.8) mm, shiny, smooth. |
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Persicaria wallichii |
Persicaria minor |
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Phenology | Flowering Jul–Oct. | |
Habitat | Damp, open places | |
Elevation | 0-100 m (0-300 ft) | |
Distribution |
CA; MA; OR; BC; Asia
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CT; IN; LA; MA; NE; PA; VA; VT; NB; ON; QC; Europe [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 minor is synonymized with P. maculosa in most North American floras; its distribution in the flora area is poorly known. Hybrids between P. minor and P. maculosa have been documented in Europe (R. H. Roberts 1977). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 581. | FNA vol. 5, p. 593. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Rubrivena | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Polygonum polystachyum, Aconogonon polystachyum, Pleuropteropyrum polystachyum, Reynoutria polystachya, Rubrivena polystachya | Polygonum minus, Polygonum minus var. subcontinuum |
Name authority | Greuter & Burdet: Willdenowia 19: 41. (1989) | (Hudson) Opiz: Seznam, 72. (1852) |
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