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, introduced 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.
... more about "Persicaria chinensis"
Harold R. Hinds† +  and Craig C. Freeman +
(Linnaeus) H. Gross +
Polygonum chinense +
Chinese knotweed +
Md. +, Mass. +, N.J. +, Asia +  and introduced also in the Pacific Islands (Hawaii). +
0–100 m +
Disturbed places +
Flowering Jul–Oct. +
Bot. Jahrb. Syst. +
Introduced +
Persicaria chinensis +
Persicaria sect. Cephalophilon +
species +