Polygonum parryi |
Polygonum erectum |
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Parry's knotweed, Parry's or prickly knotweed, prickly knotweed |
devil's shoestring, erect knotweed, renouée dressée, upright knotweed, wireweed |
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Habit | Herbs, compact, often cushion-like. | Plants light green or yellowish, heterophyllous. |
Stems | erect, green-brown, simple or branched from base, not wiry, 2–5(–8) cm, glabrous. |
erect to ascending, sparingly branched in distal 1/2, not wiry, 15–75 cm. |
Leaves | ± uniformly distributed, dense, not articulated to ocreae, basal leaves ± persistent, distal leaves gradually reduced to bracts; ocrea 2–4(–5) mm, glabrous, proximal part cylindric, distal part deeply lacerate, disintegrating into white, curled fibers; petiole absent; blade 3-veined, without pleats, linear-lanceolate, subulate, 5–13(–20) × 0.4–1 mm, margins revolute, smooth, apex spine-tipped. |
ocrea 7–12 mm, proximal part cylindric, distal part usually persistent, with strong veins, margins entire or lacerate, silvery, later disintegrating into ± persistent brown fibers; petiole 1–5 mm; blade light green or yellowish, elliptic to obovate, 30–60(–80) × (8–)10–25 mm, margins flat, apex obtuse; stem leaves 1.5–3.5(–4) times longer than branch leaves; distal leaves overtopping flowers in distal part of inflorescence. |
Inflorescences | axillary; cymes in most axils, 1-flowered. |
axillary; cymes in axils of most leaves and toward tips of stems and branchs, 1–5-flowered. |
Pedicels | absent. |
mostly exserted from ocreae, 3–7 mm. |
Flowers | closed; perianth 1.5–2(–2.5) mm; tube 6–15% of perianth length; tepals overlapping, usually reddish with white margins, petaloid, oblong, navicular, apex acute; midveins unbranched; stamens 8. |
closed; perianth 2.8–3.8(–4.2) mm; tube 20–37% of perianth length; tepals overlapping, green with yellowish, rarely whitish green, margins, sepaloid, not keeled, oblong to obovate, cucullate; midveins branched, moderately to heavily thickened; stamens 7–8. |
Achenes | slightly exserted from perianth at maturity, dark brown, ovate, 1.2–1.6(–2) mm, faces subequal, shiny, smooth. |
enclosed in perianth, brown to tan, ovate, 3-gonous, 2.3–3.5 mm, faces subequal, ± concave, apex not beaked, edges concave, dull, striate-tubercled; late-season achenes uncommon, 4–5 mm. |
Polygonum parryi |
Polygonum erectum |
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Phenology | Flowering May–July. | Flowering May–Oct. |
Habitat | Vernally moist, open, sandy or rocky places | Dry, waste ground |
Elevation | 500-2000 m (1600-6600 ft) | 10-300 m (0-1000 ft) |
Distribution |
CA; WA
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AL; AR; CO; CT; DC; DE; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; TN; VA; VT; WA; WI; WV; WY; AB; ON; QC; SK
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Discussion | Polygonum erectum was cultivated in the midwest by Native Americans for its starchy seeds (C. M. Scarry 1993). It was formerly confused with P. achoreum (T. R. Mertens and P. H. Raven 1965). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 5, p. 563. | FNA vol. 5, p. 550. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Polygonum |
Sibling taxa | ||
Name authority | Greene: Bull. Torrey Bot. Club 8: 99. (1881) | Linnaeus: Sp. Pl. 1: 363. (1753) |
Web links |
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