Polygonum aviculare subsp. aviculare

Common names: Common knotweed
WeedyIntroducedIllustrated
Synonyms: Polygonum aviculare var. eximium (Lindman) Ascherson & Graebner Polygonum aviculare subsp. heterophyllum (Thiébaut-de-Berneaud ex Persoon) Arcangeli Polygonum aviculare subsp. monspeliense Polygonum aviculare var. vegetum Ledebour Polygonum heterophyllum Polygonum monspeliense
Treatment appears in FNA Volume 5. Treatment on page 557. Mentioned on page 558.

Plants green, heterophyllous (often lacking larger proximal stem-leaves at maturity). Stems 1–3, ascending or erect, sometimes decumbent, basal branches divaricate, (10–) 25–75 (–100) cm. Leaves: ocrea (5.5–) 6–10 (–14) mm, proximal part cylindric, distal part silvery, hyaline, soon lacerate and disintegrating into fibers; petiole 1–6 (–8) mm; blade green, lateral-veins visible but not raised abaxially, elliptic to oblanceolate, 18–50 (–60) × (6–) 10–20 mm, 2–4.5 times as long as wide, apex acute or obtuse; stem-leaves 1.4–4 times as long as branch leaves. Cymes aggregated at tips of stems and branches, 3–8-flowered. Pedicels mostly exserted from ocreae, 2–5 mm. Flowers: perianth (2.3–) 2.8–4.7 (–5) mm, 1.8–2.8 times as long as wide; tube (15–) 20–37% of perianth length; tepals overlapping, green with pink, red, or white margins, oblong, flat (cucullate in fruit), outer tepals not pouched at base; veins branched, thickened; stamens 7–8. Achenes enclosed in or barely exserted from perianth, brown to dark-brown, ovate, 3-gonous, (2.1–) 2.7–3.7 mm, faces subequal, concave, apex straight, striate-tubercled; late-season achenes uncommon, 3.5–5 mm. 2n = 40, 60.


Phenology: Flowering May–Oct.
Habitat: Fields, uncultivated areas, waste places, roadsides
Elevation: 0-3500 m

Distribution

V5 1137-distribution-map.gif

Introduced; St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., La., Maine, Md., Mass., Mich., Minn., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., Wyo., Eurasia

Discussion

Selected References

None.

Lower Taxa

None.

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

0.21 cm2.1 mm <br />0.0021 m <br /> (0.27 cm2.7 mm <br />0.0027 m <br />) +
brown;dark-brown +
exserted +  and included +
dull +  and shiny +
smooth;roughened +
3-gonous +  and ovate +
whitish yellow +
elliptic +  and oblong +
striate-tubercled +
straight +
obtuse;acute +
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
Linnaeus +
75 cm750 mm <br />0.75 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not stipelike +
5 cm50 mm <br />0.05 m <br /> (6 cm60 mm <br />0.06 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (5 cm50 mm <br />0.05 m <br />) +
spatulate;obovate;spatulate;obovate;elliptic;lanceolate;elliptic +
coriaceous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
Common knotweed +
3-8-flowered +
hyaline +  and silvery +
St. Pierre and Miquelon +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. (Nfld.) +, N.W.T. +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Ala. +, Alaska +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Mont. +, Nebr. +, Nev. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, N.Dak. +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Vt. +, Va. +, Wash. +, Wyo. +  and Eurasia +
tubercled +  and striate-tubercled +
concave +
0-3500 m +
concave +
subequal +
persistent +
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, uncultivated areas, waste places, roadsides +
compound +, branched +  and simple +
nonmembranous +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
sessile +  and petiolate +
deciduous +
pubescent +  and glabrous +
lobed +, undulate +, crisped +, crenulate +  and entire +
unbranched +  and branched +
not +  and thickened +
swollen +
1 cm10 mm <br />0.01 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
silvery +, white +  and hyaline +
disintegrating +
deciduous +  and persistent +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
coriaceous +  and membranous +
somewhat larger +
anatropous +, , +  and orthotropous +
erect;spreading +
accrescent +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
spreading;erect +
0.47 cm4.7 mm <br />0.0047 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
greenish white;pink +
campanulate +  and urceolate +
nonaccrescent +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.47 cm4.7 mm <br />0.0047 m <br />) +
fleshy +, indurate +  and membranous +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Flowering May–Oct. +
(2-)3(-4)-carpellate +
slender;stout +
woody +  and fibrous +
Weedy +, Introduced +  and Illustrated +
7 +  and 8 +
1.4-4 times as long as branch leaves +
flexuous +
erect +  and ascending +
1 +  and 3 +
papillous-scabridulous +
5 cm50 mm <br />0.05 m <br /> (200 cm2,000 mm <br />2 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 aviculare var. eximium +, Polygonum aviculare subsp. heterophyllum +, Polygonum aviculare subsp. monspeliense +, Polygonum aviculare var. vegetum +, Polygonum heterophyllum +  and Polygonum monspeliense +
Polygonum aviculare subsp. aviculare +
Polygonum aviculare +
subspecies +
overlapping +
white +, red +, punct +, green with pink +, list +  and coloration +
connate +  and distinct +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
not cushionlike +