Polygonum parryi |
Polygonum argyrocoleon |
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Parry's knotweed, Parry's or prickly knotweed, prickly knotweed |
Persian knotweed, silver sheath knotweed |
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Habit | Herbs, compact, often cushion-like. | Plants green, heterophyllous. |
Stems | erect, green-brown, simple or branched from base, not wiry, 2–5(–8) cm, glabrous. |
erect or decumbent, branched mostly from base, not wiry, 15–100 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 4–8 mm, proximal part cylindric, distal part soon disintegrating into curly or straight fibers; petiole 0–1.5 mm; blade bluish green, lanceolate or linear-lanceolate, 15–50 × 2–8 mm, margins flat, apex acute; stem leaves 2.1–4 times as long as branch leaves; distal leaves abruptly reduced and not overtopping flowers (shorter than or equaling flowers). |
Inflorescence(s) | axillary; cymes in most axils, 1-flowered. |
axillary and terminal, spikelike; cymes aggregated at tips of stems and branches, 4–6-flowered, bracts inconspicuous. |
Pedicels | absent. |
enclosed in ocreae, 1–2 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 1.8–2.4 mm; tube 10–22% of perianth length; tepals overlapping, green or white, usually with pink, rarely red or white, margins, petaloid, not keeled, oblong to obovate, cucullate; midveins usually unbranched; 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, ovate, 3-gonous, 1.3–2.3 mm, faces subequal, slightly concave, apex not beaked, with concave edges, shiny, smooth; late-season achenes unknown. |
Polygonum parryi |
Polygonum argyrocoleon |
|
Phenology | Flowering May–July. | Flowering May–Oct. |
Habitat | Vernally moist, open, sandy or rocky places | Fields, gardens, disturbed sites, often in saline soils |
Elevation | 500-2000 m (1600-6600 ft) | 0-1200 m (0-3900 ft) |
Distribution |
CA; WA
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AZ; CA; CO; FL; ID; LA; MA; MO; NC; NM; NV; TX; UT; VT; WV; c Asia [Introduced in North America]
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Source | FNA vol. 5, p. 563. | FNA vol. 5, p. 560. |
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) | Steudel ex Kunze: Linnaea 20: 17. (1847) |
Web links |
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