Persicaria chinensis

(Linnaeus) H. Gross

Bot. Jahrb. Syst. 49: 269. 1913.

Common names: Chinese knotweed
Introduced
Basionym: Polygonum chinense Linnaeus Sp. Pl. 1: 363. 1753
Treatment appears in FNA Volume 5. Treatment on page 580. Mentioned on page 579.

Plants perennial, 7–10 dm; roots not also arising from proximal nodes; rhizomes present. Stems ascending to erect, sometimes scandent, glabrous or retrorsely hispid. Leaves: ocrea brownish, cylindric, 15–25 (–50) mm, coriaceous proximally, chartaceous distally, base often inflated, margins oblique, eciliate, surface glabrous or pubescent; petiole 1–2.5 cm, winged at least distally; blade lanceolate to ovate or elliptic, 4–16 × 1.5–8 cm, base truncate to broadly cordate, margins glabrous or antrorsely scabrous with whitish hairs, apex acuminate, faces glabrous or hispid abaxially and adaxially, sometimes pubescent only along veins abaxially, not glandular-punctate but often minutely reddish-punctate abaxially. Inflorescences terminal or terminal and axillary, 3–6 × 3–6 mm; peduncle 10–30 mm, stipitate-glandular along entire length; ocreolae overlapping, margins eciliate. Pedicels mostly ascending, 2–3 mm. Flowers 1–3 per ocreate fascicle; perianth white to pink, campanulate, glabrous, accrescent; tepals 5, ovate, 3–4 mm, apex acute to obtuse; stamens 8, filaments distinct, free; anthers red or purple, elliptic; styles 3, connate proximally. Achenes included in fleshy, bluish black perianth, black, 3-gonous, 2.8–4 × 2–3 mm, dull, minutely punctuate.


Phenology: Flowering Jul–Oct.
Habitat: Disturbed places
Elevation: 0–100 m

Distribution

V5 1188-distribution-map.gif

Introduced; Md., Mass., N.J., Asia, also in the Pacific Islands (Hawaii)

Discussion

Varieties of Persicaria chinensis have been distinguished on the basis of stem pubescence, leaf shape, and leaf size. Whether those taxa merit recognition in the flora area is uncertain.

Selected References

None.

Lower Taxa

None.

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

... more about "Persicaria chinensis"
0.28 cm2.8 mm <br />0.0028 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
exserted +  and included +
3-gonous +
purple +  and red +
elliptic +  and ovate +
acute;obtuse +
not +  and swollen +
Harold R. Hinds† +  and Craig C. Freeman +
(Linnaeus) H. Gross +
truncate +  and broadly cordate +
Polygonum chinense +
4 cm40 mm <br />0.04 m <br /> (16 cm160 mm <br />0.16 m <br />) +
lanceolate;ovate or elliptic +
1.5 cm15 mm <br />0.015 m <br /> (8 cm80 mm <br />0.08 m <br />) +
lunate +, triangular +  and dark +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
Chinese knotweed +
Md. +, Mass. +, N.J. +, Asia +  and also in the Pacific Islands (Hawaii) +
0–100 m +
reddish-punctate +  and not glandular-punctate +
pubescent +, hispid +  and glabrous +
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 +
Disturbed places +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
capitate +, paniclelike +  and spikelike +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
nonmembranous +
sessile +  and petiolate +
deciduous +
eciliate +, scabrous +  and glabrous +
swollen +
2.5 cm25 mm <br />0.025 m <br /> (5 cm50 mm <br />0.05 m <br />) +
disintegrating +
deciduous +  and persistent +
scabrous +  and variously pubescent +
cylindric +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
coriaceous +
anatropous +, , +  and orthotropous +
accrescent +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
spreading;erect +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
bluish black;white;pink +
campanulate +
accrescent +
auriculate +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Flowering Jul–Oct. +
(2-)3(-4)-carpellate +
Bot. Jahrb. Syst. +
slender;stout +
Introduced +
unarmed +  and branched +
decumbent to ascending or erect +  and prostrate +
ascending +  and erect +
hispid +  and glabrous +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
deciduous +
spreading;erect +
pubescent +  and glabrous +
Persicaria chinensis +
Persicaria sect. Cephalophilon +
species +
1/3 +  and 1/2 +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
stoloniferous +, rhizomatous +, fibrous-rooted +  and taprooted +
12 +, 11 +  and 10 +