Persicaria punctata |
Persicaria hydropiperoides |
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dotted knotweed, dotted smartweed, renouée ponctuée, water smartweed |
false water pepper, false water-pepper smartweed, mild waterpepper, renouée faux-poivre-d'eau, swamp smartweed, water-pepper |
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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, 1.5–10 dm; roots also often arising from proximal nodes; rhizomes often present. |
Stems | ascending to erect, branched, without noticeable ribs, glabrous, glandular-punctate. |
decumbent to ascending, usually branched, without noticeable ribs, glabrous or obscurely strigose distally. |
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 brown, cylindric, 5–23 mm, chartaceous, base inflated, margins truncate, ciliate with bristles (2–)4–10 mm, surface glabrous or strigose, not glandular-punctate; petiole 0.2–2 cm, glabrous or strigose; blade without dark triangular or lunate blotch adaxially, broadly lanceolate to linear-lanceolate, 5–25 × 0.4–3.7 cm, base tapered or acute, margins antrorsely appressed-pubescent, apex acuminate, faces glabrous or appressed-pubescent along midveins and sometimes on faces, usually punctate abaxially. |
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. |
terminal, sometimes also axillary, erect, uninterrupted or interrupted proximally, 30–80 × 2–5 mm; peduncle 10–30 mm, glabrous or strigose; ocreolae overlapping distally, often not overlapping proximally, margins ciliate with bristles to 2(–3) mm. |
Pedicels | ascending, 1–4 mm. |
ascending, 1–1.5 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. |
bisexual or unisexual and staminate, 2–6 per ocreate fascicle, homostylous; perianth roseate proximally, roseate, white, or greenish white distally, not glandular-punctate or sometimes glandular-punctate with punctae on tubes and inner tepals, scarcely accrescent; tepals 5, connate ca. 1/3–1/2 their length, obovate, 2.5–4 mm in bisexual flowers, 1.5–2.5 mm in staminate flowers, veins prominent or not, not anchor-shaped, margins entire, apex obtuse to rounded; stamens 8, included or exserted in staminate flowers; anthers pink or red, elliptic to ovate; styles 3, connate near middle. |
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 or apex exserted, brown to brownish black or black, 3-gonous, 1.5–3 × 1–2.3 mm, shiny, smooth. |
2n | = 44. |
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Persicaria punctata |
Persicaria hydropiperoides |
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Phenology | Flowering Jun–Nov. | Flowering Jun–Nov. |
Habitat | Shallow water, shores, marshes, floodplain forests | Wet banks and clearings, shallow water, marshes, moist prairies, ditches |
Elevation | 0-1500 m [0-4900 ft] | 0-1500 m [0-4900 ft] |
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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AK; AL; AR; AZ; CA; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; VA; VT; WA; WI; WV; BC; NB; NS; ON; QC; Mexico; Central America; South America
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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.) |
The extreme variability in Persicaria hydropiperoides is reflected in its extensive synonymy. Among the segregates most often recognized in floras and checklists is P. opelousana, which C. B. McDonald (1980) showed to be broadly sympatric and highly interfertile with P. hydropiperoides. Consistent with this conclusion, R. S. Mitchell (1971) found that P. hydropiperoides and P. opelousana are unique among native North American smartweeds in consistently possessing multicellular plate-glands on the abaxial surface of their leaves. Such glands also are found on P. maculosa, an introduced European species. Herbarium specimens of Persicaria hydropiperoides sometimes are misidentified as P. maculosa, especially when the roots are missing. The former species may be distinguished reliably by its achenes all trigonous (trigonous and biconvex achenes are mixed in the inflorescences of P. maculosa) and bristles on the margins of the ocreae that average longer. M. L. Fernald (1922c) reported hybrids with P. robustior from Nova Scotia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 586. | FNA vol. 5, p. 585. |
Parent taxa | ||
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 hydropiperoides, P. opelousana, P. paludicola, Polygonum hydropiperoides var. adenocalyx, Polygonum hydropiperoides var. asperifolium, Polygonum hydropiperoides var. breviciliatum, Polygonum hydropiperoides var. bushianum, Polygonum hydropiperoides var. digitatum, Polygonum hydropiperoides var. opelousanum, Polygonum hydropiperoides var. psilostachyum, Polygonum opelousanum, Polygonum opelousanum var. adenocalyx |
Name authority | (Elliott) Small: Fl. S.E. U.S., 379. (1903) | (Michaux) Small: Fl. S.E. U.S., 378. (1903) |
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