Polygonum argyrocoleon

Steudel ex Kunze

Linnaea 20: 17. 1847.

Common names: Persian or silversheath knotweed
WeedyIntroduced
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

Distribution

V5 1144-distribution-map.gif

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

Discussion

Selected References

None.

Lower Taxa

None.

"/2" is not declared as a valid unit of measurement for this property.

... more about "Polygonum argyrocoleon"
exserted +  and included +
dull +  and shiny +
smooth;roughened +
3-gonous +  and ovate +
whitish yellow +
elliptic +  and oblong +
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
Steudel ex Kunze +
not stipelike +
bluish green +
1.5 cm15 mm <br />0.015 m <br /> (5 cm50 mm <br />0.05 m <br />) +
linear-lanceolate;lanceolate +
coriaceous +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
foliaceous +  and perfoliate +
inconspicuous +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
Persian or silversheath knotweed +
4-6-flowered +
Ariz. +, Calif. +, Colo. +, Fla. +, Idaho +, La. +, Mass. +, Mo. +, Nev. +, N.Mex. +, N.C. +, Tex. +, Utah +, Vt. +, W.Va. +  and c Asia +
concave +
0-1200 m +
concave +
subequal +
straight +
adnate +, free +  and distinct +
disarticulating +  and solid +
decumbent to erect +  and prostrate +
unwinged +  and winged +
black +, red +, brown +  and yellowish +
exserted +  and included +
pubescent +  and glabrous +
spheroidal +, 4-gonous +, lenticular +, biconvex +, discoid +, 3-gonous +  and 2-gonous +
Fields, gardens, disturbed sites, often in saline soils +
compound +, branched +  and simple +
nonmembranous +
sessile +  and petiolate +
deciduous +
pubescent +  and glabrous +
cucullate +, oblong +  and obovate +
swollen +
silvery +, white +  and hyaline +
disintegrating +
deciduous +  and persistent +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
coriaceous +  and membranous +
somewhat larger +
anatropous +, , +  and orthotropous +
erect;spreading +
accrescent +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
spreading;erect +
greenish white;pink +
campanulate +  and urceolate +
nonaccrescent +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
fleshy +, indurate +  and membranous +
0 cm0 mm <br />0 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Flowering May–Oct. +
(2-)3(-4)-carpellate +
slender;stout +
woody +  and fibrous +
Weedy +  and Introduced +
7 +  and 8 +
2.1-4 times as long as branch leaves +
not wiry +  and branched +
straight +
decumbent +  and erect +
papillous-scabridulous +
15 cm150 mm <br />0.15 m <br /> (100 cm1,000 mm <br />1 m <br />) +
2 +  and 3 +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
connate +  and distinct +
spreading;erect +
Polygonum argyrocoleon +
Polygonum sect. Polygonum +
species +
overlapping +
white +, red +  and green +
connate +  and distinct +
lobed +  and laciniate +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
not cushionlike +