Polygonum minimum |
Polygonum argyrocoleon |
|
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broad-leaf knotweed, broad-leaf or leafy dwarf knotweed, leafy dwarf knotweed, little mountain knotweed, zigzag knotweed |
Persian knotweed, silver sheath knotweed |
|
Habit | Herbs. | Plants green, heterophyllous. |
Stems | prostrate to erect, often zigzagged, reddish brown, simple or branched from base, wiry, 2–30 cm, papillose-scabrid-ulous. |
erect or decumbent, branched mostly from base, not wiry, 15–100 cm. |
Leaves | evenly distributed or crowded at branch tips, articulated to ocreae, basal leaves persistent, hardly reduced distally; ocrea 1–4 mm, papillose-scabridulous, proximal part cylindric, distal part entire or dentate-lacerate; petiole 0.1–3 mm; blade 1-veined, not pleated, narrowly elliptic, elliptic, ovate, obovate, or subround, 6–27 × 3–8 mm, margins flat, smooth, irregularly thickened or papillose-denticulate, apex apiculate, green adaxially. |
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 from near stem and branch bases, sometimes also crowded at branch apices, 1–3-flowered. |
axillary and terminal, spikelike; cymes aggregated at tips of stems and branches, 4–6-flowered, bracts inconspicuous. |
Pedicels | enclosed in ocreae, erect to spreading, 2–3 mm. |
enclosed in ocreae, 1–2 mm. |
Flowers | semi-open or closed; perianth 1.8–2.5 mm; tube 22–29% of perianth length; tepals overlapping, greenish with narrow white or pink margins, almost sepaloid, oblong, cucullate, ± navicular, apex rounded; midveins thickened, 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 | enclosed in perianth or tip exserted, black, elliptic to ovate, 1.8–2.3 mm, faces subequal, smooth, shiny. |
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 minimum |
Polygonum argyrocoleon |
|
Phenology | Flowering Jul–Sep. | Flowering May–Oct. |
Habitat | Alpine to subalpine sites, open or semibarren soil | Fields, gardens, disturbed sites, often in saline soils |
Elevation | 1500-3300 m (4900-10800 ft) | 0-1200 m (0-3900 ft) |
Distribution |
AK; CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC
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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. 569. | FNA vol. 5, p. 560. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Duravia | Polygonaceae > subfam. Polygonoideae > Polygonum > sect. Polygonum |
Sibling taxa | ||
Synonyms | P. torreyi | |
Name authority | S. Watson: Botany (Fortieth Parallel), 315. (1871) | Steudel ex Kunze: Linnaea 20: 17. (1847) |
Web links |
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