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dotted knotweed, dotted smartweed, renouée ponctuée, water smartweed

jumpseed, renouée de virginie

Habit Plants annual or perennial, 1.5–12 dm; roots also often arising from proximal nodes; rhizomes often present. Plants perennial, 4.5–6(–13) dm; rhizomatous.
Stems

ascending to erect, branched, without noticeable ribs, glabrous, glandular-punctate.

ribbed, glabrous or strigose.

Leaves

ocrea brown, cylindric, (4–)9–18 mm, chartaceous, base inflated, margins truncate, ciliate with bristles 2–11 mm, surface glabrous or strigose, glandular-punctate;

petiole 0.1–1 cm, glandular-punctate, leaves sometimes sessile;

blade without dark triangular or lunate blotch adaxially, lanceolate to lanceolate-ovate or subrhombic, 4–10(–15) × 0.6–2.4 cm, base tapered or cuneate, margins antrorsely strigose, apex acute to acuminate, faces glabrous or scabrous along midveins, glandular-punctate.

ocrea brownish hyaline, cylindric, 10–20 mm, base inflated or not, margins truncate, ciliate with bristles 0.5–4 mm, surface strigose to tomentose;

petiole (0.1–)1–2 cm, leaves sometimes sessile;

blade 5–17.5 × 2–10 cm, apex acute to acuminate, faces pubescent abaxially, strigose and scabrous adaxially.

Inflorescences

mostly terminal, sometimes also axillary, erect, interrupted, 50–200 × 4–8 mm;

peduncle 30–60 mm, glabrous, glandular-punctate;

ocreolae mostly not overlapping, margins mostly ciliate with bristles to 2 mm.

(50–)100–350 × 7–15 mm;

peduncle 10–70 mm, pubescent or glabrous distally;

ocreolae not overlapping, margins ciliate with bristles to 3 mm.

Pedicels

ascending, 1–4 mm.

ascending to spreading, 0.5–1 mm.

Flowers

2–6 per ocreate fascicle, homostylous;

perianth greenish proximally, white distally, rarely tinged pink, glandular-punctate with punctae ± uniformly distributed, scarcely accrescent;

tepals 5, connate ca. 1/3 their length, obovate, 3–3.5 mm, veins prominent or not, not anchor-shaped, margins entire, apex obtuse to rounded;

stamens 6–8, included;

anthers pink or red, elliptic to ovate;

styles 2–3, connate proximally.

1–3 per ocreate fascicle;

perianth white, greenish white, or rarely pink, glabrous, accrescent;

tepals elliptic to obovate, 2.5–3.5 mm, apex acute to acuminate;

filaments distinct, outer ones sometimes adnate to perianth tube;

anthers yellow or pink, ovate;

styles distinct.

Achenes

included or apex exserted, brownish black, usually 3-gonous, rarely biconvex, (1.8–)2.2–3.2 × 1.5–2.2 mm, shiny, smooth.

included except for apex and styles, brown to dark brown, biconvex, 3.5–4 × 2–2.8 mm, dull to shiny, smooth to rugose.

2n

= 44.

= 44.

Persicaria punctata

Persicaria virginiana

Phenology Flowering Jun–Nov. Flowering Jul–Oct.
Habitat Shallow water, shores, marshes, floodplain forests Rich deciduous forests, floodplain forests, dry woodlands, thickets
Elevation 0-1500 m (0-4900 ft) 0-500 m (0-1600 ft)
Distribution
from FNA
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; VA; VT; WA; WI; WV; WY; HI; BC; MB; NB; NS; ON; PE; QC; SK; Mexico; West Indies (Puerto Rico); Central America (Guatemala); South America (Brazil)
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WI; WV; ON; QC; c Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

N. C. Fassett (1949) proposed a complicated classification for Persicaria punctata with 12 varieties in North America and South America. He also identified numerous specimens that he considered to be morphologically intermediate between various varieties. M. Dalci (1972) documented a wide range of phenotypic and genotypic variation throughout the range of P. punctata and extensive overlap in many of the features used by Fassett to distinguish varieties. Consequently, recognition of varieties does not seem warranted. Persicaria punctata and its close relatives P. robustior and P. glabra are unique among native North American smartweeds in possessing complex glands called valvate chambers in their epidermises. Persicaria punctata is confused most frequently with P. hydropiper; the achenes are diagnostic.

The Chippewa, Houma, and Iroquois prepared decoctions from leaves, flowers, and roots for use as analgesics as well as gastrointestinal, orthopedic, and psychological aids (D. E. Moerman 1998).

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

Tension in the articulation of the pedicels is sufficient to throw mature achenes 3–4 m when the inflorescence is bumped, and the persistent, hooked styles aid in the dispersal of achenes in the fur of animals (H. S. Reed and I. Smoot 1906). A hot infusion of leaves with bark of honey-locust (Gleditsia triacanthos Linnaeus) was used by the Cherokee to treat whooping cough (D. E. Moerman 1998).

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

Source FNA vol. 5, p. 586. FNA vol. 5, p. 575.
Parent taxa Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Tovara
Sibling taxa
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. 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. robustior, P. sagittata, P. setacea, P. wallichii
Synonyms Polygonum punctatum, Polygonum acre var. leptostachyum, Polygonum punctatum var. confertiflorum, Polygonum punctatum var. ellipticum, Polygonum punctatum var. leptostachyum, Polygonum punctatum var. parviflorum, Polygonum punctatum var. parvum Polygonum virginianum, Antenoron virginianum, Tovara virginiana
Name authority (Elliott) Small: Fl. S.E. U.S., 379. (1903) (Linnaeus) Gaertner: Fruct. Sem. Pl. 2: 180. (1790)
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