Polygonum parryi |
Polygonum heterosepalum |
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Parry's knotweed, Parry's or prickly knotweed, prickly knotweed |
dwarf desert knotweed, odd-sepal knotweed |
|
Habit | Herbs, compact, often cushion-like. | Herbs, compact, often cushion-like. |
Stems | erect, green-brown, simple or branched from base, not wiry, 2–5(–8) cm, glabrous. |
erect, green or reddish, simple or branched near base, not wiry, 1.5–5 cm, glabrous. |
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. |
uniformly distributed, dense, not articulated to ocreae, basal leaves persistent or caducous, distal leaves gradually reduced to bracts; ocrea 3–6 mm, glabrous, proximal part cylindric, distal part disintegrating almost to base, with whitish, straight, rigid fibers; petiole absent; blade 3-veined, without pleats, linear to lanceolate, 10–20 × 0.6–2.7 mm, margins revolute, smooth, apex spine-tipped. |
Inflorescences | axillary; cymes in most axils, 1-flowered. |
axillary; cymes in most axils, 2–3-flowered. |
Pedicels | absent. |
enclosed in ocreae, erect, 0.1–1 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 2.3–2.7 mm; tube 3–7% of perianth length; tepals overlapping, whitish with whitish or pink margins, petaloid, oblong, navicular, dimorphic, outer 2 shorter than inner 3, outer 2 0.8–1.2 mm, inner 2.3–2.7 mm, papillose at base, apex acute or acuminate; midveins unbranched; stamens 5–6. |
Achenes | slightly exserted from perianth at maturity, dark brown, ovate, 1.2–1.6(–2) mm, faces subequal, shiny, smooth. |
enclosed in perianth, olive brown, narrowly ovate to ovate-lanceolate, 1.5–2 mm, faces subequal, shiny, smooth. |
Polygonum parryi |
Polygonum heterosepalum |
|
Phenology | Flowering May–July. | Flowering Jun–Aug. |
Habitat | Vernally moist, open, sandy or rocky places | Dry waste ground, open flats in sagebrush plains, ponderosa pine forests |
Elevation | 500-2000 m (1600-6600 ft) | 1000-1500 m (3300-4900 ft) |
Distribution |
CA; WA
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ID; NV; OR |
Discussion | Of conservation concern. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 5, p. 563. | FNA vol. 5, p. 563. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia |
Sibling taxa | ||
Name authority | Greene: Bull. Torrey Bot. Club 8: 99. (1881) | M. Peck & Ownbey: Madroño 10: 250. (1950) |
Web links |
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