Persicaria punctata |
Persicaria glabra |
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dotted knotweed, dotted smartweed, renouée ponctuée, water smartweed |
denseflower knotweed, smooth smartweed |
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Habit | Plants annual or perennial, 1.5–12 dm; roots also often arising from proximal nodes; rhizomes often present. | Plants perennial, 3–15 dm; roots also often arising from proximal nodes; rhizomes present. |
Stems | ascending to erect, branched, without noticeable ribs, glabrous, glandular-punctate. |
decumbent to erect, usually branched distally, without noticeable ribs, glabrous or, rarely, pubescent distally, sometimes glandular-punctate. |
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 light brown, cylindric, 12–23 mm, chartaceous, base inflated, margins truncate, eciliate, surface glabrous, usually obscurely glandular-punctate; petiole 0.2–2 cm, scabrous; blade without dark triangular or lunate blotch adaxially, lanceolate, (10–)15–30 × (1.5–)2–5.4 cm, base tapered, margins glabrous or antrorsely strigose, apex acute to acuminate, faces glabrous or scabrous along midveins, sometimes glandular-punctate. |
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. |
mostly terminal, sometimes also axillary, erect to slightly nodding, usually uninterrupted, 30–100 × 5–9 mm; peduncle 10–50 mm, glabrous or scabrid, glandular-punctate; ocreolae usually overlapping, margins eciliate. |
Pedicels | ascending, 1–4 mm. |
erect to spreading, 2–5 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–)3–8 per ocreate fascicle, homostylous; perianth greenish white to white or pink, glabrous, not glandular-puncate or glandular-punctate with punctae ± uniformly distributed, scarcely accrescent; tepals 5, connate ca. 1/3 their length, obovate, 3–3.6 mm, veins not prominent, not anchor shaped, margins entire, apex obtuse to rounded; stamens 5–7, included; anthers pink or red, ovate; styles 2, connate proximally. |
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, dark brown to brownish black, biconvex, 2–2.2 × 1.3–1.6 mm, shiny, smooth. |
2n | = 44. |
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Persicaria punctata |
Persicaria glabra |
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Phenology | Flowering Jun–Nov. | Flowering Aug–Nov. |
Habitat | Shallow water, shores, marshes, floodplain forests | Swamps, wet thickets, marshy shores, frequently in water, mostly on coastal plain of e North America |
Elevation | 0-1500 m (0-4900 ft) | 0-300 |
Distribution |
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)
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AL; AR; DE; FL; GA; KY; LA; MD; MO; MS; NC; NJ; SC; TN; TX; VA; Central America; South America; Asia; ne Africa; Pacific Islands (Hawaii, Philippines)
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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.) |
American plants here included in Persicaria glabra often have been treated as distinct and called P. densiflora. The morphological differences between them and Asian and Pacific P. glabra are minor. Regional tendencies exist but do not appear sufficient to warrant separation of the species (K. L. Wilson 1990b). An infusion made from pounded whole plants was used by the Hawaiians as a blood medicine (D. E. Moerman 1998). Persicaria portoricensis Small and Polygonum portoricense Bertero ex Small are superfluous and illegitimate names that pertain here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 586. | FNA vol. 5, p. 586. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria |
Sibling taxa | ||
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 glabrum, P. densiflora, Polygonum densiflorum |
Name authority | (Elliott) Small: Fl. S.E. U.S., 379. (1903) | (Willdenow) M. Gómez: Anales Inst. Segunda Enseñ. 2: 278. (1896) |
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