Polygonum parryi |
Polygonum oxyspermum |
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Parry's knotweed, Parry's or prickly knotweed, prickly knotweed |
knotweed, sharp-fruit knotweed |
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Habit | Herbs, compact, often cushion-like. | Plants green to blue-green, homophyllous. | ||||
Stems | erect, green-brown, simple or branched from base, not wiry, 2–5(–8) cm, glabrous. |
prostrate to ascending, branched at proximal and middle nodes, not wiry, 20–100 cm. |
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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 6.5–12 mm, proximal part cylindric, pruinose, distal part hyaline, soon disintegrating into brown fibers or nearly completely deciduous; petiole 0–1 mm; blade green to bluish green, elliptic-lanceolate to linear, 10–35 × 1.5–15 mm, margins flat or narrowly revolute, apex acute; middle stem leaves slightly larger than adjacent branch leaves, distal leaves overtopping flowers. |
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Inflorescences | axillary; cymes in most axils, 1-flowered. |
axillary, cymes uniformly distributed, 2–7-flowered. |
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Pedicels | absent. |
exserted from ocreae, 2.5–5(–7) mm. |
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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. |
semi-open; perianth 3.5–5.5 mm; tube 28–39% of perianth length; tepals slightly overlapping, green, margins white to pink, petaloid, not keeled, oblong to obovate, not cucullate; veins branched; stamens 8. |
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Achenes | slightly exserted from perianth at maturity, dark brown, ovate, 1.2–1.6(–2) mm, faces subequal, shiny, smooth. |
exserted from perianth, pale brown to dark brown, ovate, 3-gonous, (3.5–)4.1–5.5(–6.5) mm, faces subequal, apex not beaked, edges straight, shiny, smooth or with fine tubercles especially toward apex; late-season achenes unknown. |
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Polygonum parryi |
Polygonum oxyspermum |
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Phenology | Flowering May–July. | |||||
Habitat | Vernally moist, open, sandy or rocky places | |||||
Elevation | 500-2000 m (1600-6600 ft) | |||||
Distribution |
CA; WA
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ME; NB; NF; NS; PE; QC; Europe |
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Discussion | Subspecies 3 (2 in the flora). The treatment by D. A. Webb and A. O. Chater (1963) of the Polygonum oxyspermum complex is followed here. T. Karlsson (2000) accepted P. raii and P. oxyspermum as distinct species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 5, p. 563. | FNA vol. 5, p. 554. | ||||
Parent taxa | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Polygonum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Greene: Bull. Torrey Bot. Club 8: 99. (1881) | C. A. Meyer & Bunge ex Ledebour: Index Seminum (Dorpat) 1824: 5. (1824) | ||||
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