Polygonum argyrocoleon

Steudel ex Kunze

Linnaea 20: 17. 1847.

Common names: Persian or silversheath knotweed
Treatment appears in FNA Volume 5. Treatment on page 560. Mentioned on page 549.

Plants green, heterophyllous. Stems erect or decumbent, branched mostly from base, not wiry, 15–100 cm. Leaves: 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 axillary and terminal, spikelike; cymes aggregated at tips of stems and branches, 4–6-flowered, bracts inconspicuous. Pedicels enclosed in ocreae, 1–2 mm. Flowers 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, 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.

Phenology: Flowering May–Oct.
Habitat: Fields, gardens, disturbed sites, often in saline soils
Elevation: 0-1200 m


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Introduced; Ariz., Calif., Colo., Fla., Idaho, La., Mass., Mo., Nev., N.Mex., N.C., Tex., Utah, Vt., W.Va., c Asia.


Selected References


Lower Taxa

... more about "Polygonum argyrocoleon"
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
Steudel ex Kunze +
Persian or silversheath knotweed +
Ariz. +, Calif. +, Colo. +, Fla. +, Idaho +, La. +, Mass. +, Mo. +, Nev. +, N.Mex. +, N.C. +, Tex. +, Utah +, Vt. +, W.Va. +  and c Asia. +
0-1200 m +
Fields, gardens, disturbed sites, often in saline soils +
Flowering May–Oct. +
Weedy +  and Introduced +
Polygonum argyrocoleon +
Polygonum sect. Polygonum +
species +