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Himalayan smartweed, Japanese knotweed, pink bubble persicaria, pink-head knotweed, pink-head persicaria, pinkhead smartweed

r enouée robuste, stout dotted smartweed, stout smartweed

Habit Plants annual or perennial, 0.5–5 dm; roots also often arising from proximal nodes. Plants perennial, 3–20 dm; roots also sometimes arising from proximal nodes; rhizomes present, stolons sometimes present.
Stems

prostrate, glabrous or glandular-pubescent.

ascending, usually branched proximally, scarcely ribbed, glabrous, glandular-punctate;

branches sometimes creeping and rooting at nodes.

Leaves

ocrea brown or reddish brown, cylindric to funnelform, 5–12 mm, chartaceous, base inflated or not, margins oblique, eciliate or ciliate with bristles to 1.5 mm, surface lanate, sometimes also glandular-pubescent;

petiole 2–5 mm, winged distally;

blade ovate to elliptic, 1.5–4(–6) × 0.6–2.5(–3.3) cm, base cuneate or tapering, margins ciliate with reddish, multicellular hairs, apex acute, faces glandular-pubescent abaxially and adaxially, not glandular-punctate.

ocrea light brown, cylindric, 10–15 mm, chartaceous, base inflated, margins truncate, ciliate with bristles 3–12 mm, surface strigose, glandular-punctate;

petiole 0.2–2 cm, glandular-punctate;

blade without dark triangular or lunate blotch adaxially, lanceolate to elliptic-lanceolate, 4–20 × 2–4.5 cm, base tapered, margins antrorsely strigose, apex acute to acuminate, faces glabrous or main veins scabrous, glandular-punctate.

Inflorescences

terminal, 5–20 × 7-18 mm;

peduncle 10–40 mm, glabrous or stipitate-glandular in distal 1/5;

ocreolae overlapping, margins eciliate.

terminal and axillary, erect, uninterrupted, 20–80 × 5–10 mm;

peduncle 5–40 mm, glandular-punctate;

ocreolae usually overlapping, margins eciliate or proximal ones sometimes ciliate with bristles to 1 mm.

Pedicels

spreading, 0.5–1 mm.

ascending to spreading, 2–5 mm.

Flowers

1–5 per ocreate fascicle;

perianth greenish white proximally, pinkish distally, urceolate, glabrous, nonaccrescent;

tepals 5, elliptic, 2–3 mm, apex acute to obtuse;

stamens 8, filaments distinct, free;

anthers pink to red, elliptic;

styles 3, connate to middle or distally.

2–4 per ocreate fascicle, homostylous;

perianth greenish proximally, white distally, glandular-punctate with punctae ± uniformly distributed, slightly accrescent;

tepals 5, connate ca.1/3 their length, obovate, 3.2–4.2 mm, veins prominent or not, not anchor-shaped, margins entire, apex obtuse to rounded;

stamens 6–8, included;

anthers pink or red, elliptic;

styles 3, connate proximally.

Achenes

included, reddish brown to brownish black, 3-gonous, 1.5–2.2 × 1–1.5 mm, shiny, smooth or minutely punctate.

included or apex exserted, dark brown to brownish black, 3-gonous, 2.7–3.6 × 2–2.5 mm, shiny, smooth.

Persicaria capitata

Persicaria robustior

Phenology Flowering Jun–Sep. Flowering Jul–Oct.
Habitat Disturbed, urban places Peaty shores, often in water on coastal plain or near coast
Elevation 0-500 m (0-1600 ft) 0-1500 m (0-4900 ft)
Distribution
from FNA
CA; LA; OR; Asia (Bhutan, w China, n India, Nepal) [Introduced in North America; introduced also in the Pacific Islands (Hawaii)]
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; DE; FL; IN; KY; MA; MD; ME; MI; MO; NH; NJ; NY; OH; PA; RI; TX; VA; NS; ON; QC; Central America; South America; West Indies
[WildflowerSearch map]
[BONAP county map]
Discussion

Persicaria capitata is planted as a garden groundcover. It escapes infrequently in the flora area; once established outside of cultivation it can be difficult to eradicate.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Persicaria robustior often is synonymized with P. punctata.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 579. FNA vol. 5, p. 584.
Parent taxa Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Cephalophilon Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria
Sibling taxa
P. amphibia, P. arifolia, P. bicornis, P. bungeana, P. careyi, P. chinensis, P. glabra, P. hirsuta, P. hydropiper, P. hydropiperoides, P. lapathifolia, P. longiseta, P. maculosa, P. meisneriana, P. minor, P. nepalensis, P. orientalis, P. pensylvanica, P. perfoliata, P. punctata, P. robustior, P. sagittata, P. setacea, P. virginiana, P. wallichii
P. amphibia, P. arifolia, P. bicornis, P. bungeana, P. capitata, P. careyi, P. chinensis, P. glabra, P. hirsuta, P. hydropiper, P. hydropiperoides, P. lapathifolia, P. longiseta, P. maculosa, P. meisneriana, P. minor, P. nepalensis, P. orientalis, P. pensylvanica, P. perfoliata, P. punctata, P. sagittata, P. setacea, P. virginiana, P. wallichii
Synonyms Polygonum capitatum Polygonum punctatum var. robustius, P. punctata var. robustior, Polygonum punctatum var. majus, Polygonum robustius
Name authority (Buchanan-Hamilton ex D. Don) H. Gross: Bot. Jahrb. Syst. 49: 277. (1913) (Small) E. P. Bicknell: Bull. Torrey Bot. Club 36: 455. (1909)
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