Polygonum paronychia |
Polygonum heterosepalum |
|
---|---|---|
beach knotweed, beach or black or dune knotweed, black knotweed, dune knotweed |
dwarf desert knotweed, odd-sepal knotweed |
|
Habit | Shrubs or subshrubs. | Herbs, compact, often cushion-like. |
Stems | prostrate or ascending, brown, branched, rooting at nodes, not wiry, 10–100 cm, glabrous, covered with remains of lacerate, hyaline ocreae. |
erect, green or reddish, simple or branched near base, not wiry, 1.5–5 cm, glabrous. |
Leaves | crowded at branch tips, articulated to ocreae, basal leaves caducous or persistent, distal leaves not reduced in size; ocrea 15–20 mm, glabrous, proximal part cylindric to funnelform, distal part silvery, entire or slightly lacerate, disintegrating into persistent white-gray curly fibers; petiole 0–0.5 mm; blade 1-veined, without pleats, linear to oblanceolate, (5–)10–20(–33) × 3–8 mm, coriaceous, margins revolute, smooth, apex acute or mucronate. |
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 crowded in distal axils, 2–5-flowered. |
axillary; cymes in most axils, 2–3-flowered. |
Pedicels | enclosed in ocreae, erect to spreading, 2–5 mm. |
enclosed in ocreae, erect, 0.1–1 mm. |
Flowers | semi-open or open; perianth (4.5–)6–10 mm; tube 22–48% of perianth length; tepals partially overlapping, uniformly pink or white, reddish brown when dried, petaloid, oblong-ovate to ± lanceolate, apex rounded; midveins pinnately branched; 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 | enclosed in or slightly exserted from perianth, black, ovate, 4–5 mm, faces subequal, shiny, smooth. |
enclosed in perianth, olive brown, narrowly ovate to ovate-lanceolate, 1.5–2 mm, faces subequal, shiny, smooth. |
Polygonum paronychia |
Polygonum heterosepalum |
|
Phenology | Flowering Mar–Sep. | Flowering Jun–Aug. |
Habitat | Coastal sands, scrub along coast | Dry waste ground, open flats in sagebrush plains, ponderosa pine forests |
Elevation | 0-50 m (0-200 ft) | 1000-1500 m (3300-4900 ft) |
Distribution |
CA; OR; WA; BC
|
ID; NV; OR |
Discussion | Polygonum paronychia may be cultivated in rock gardens in open sites with sandy soil. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 562. | FNA vol. 5, p. 563. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia |
Sibling taxa | ||
Name authority | Chamisso & Schlechtendal: Linnaea 3: 51. (1828) | M. Peck & Ownbey: Madroño 10: 250. (1950) |
Web links |
|