Persicaria punctata |
Persicaria sagittata |
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dotted knotweed, dotted smartweed, renouée ponctuée, water smartweed |
arrow-leaf knotweed, arrow-leaf tearthumb, arrow-vine, renouée sagittée |
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Habit | Plants annual or perennial, 1.5–12 dm; roots also often arising from proximal nodes; rhizomes often present. | Plants annual, 3–20 dm; roots also often arising from proximal nodes. |
Stems | ascending to erect, branched, without noticeable ribs, glabrous, glandular-punctate. |
scandent, ribbed, glabrous; prickles 1–1.5 mm. |
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, cylindric, (3–)5–13 mm, chartaceous, base inflated or not, without prickles, margins oblique, glabrous or ciliate at tip with bristles 0.2–1 mm, surface glabrous; petiole 0.5–4 cm; blade broadly lanceolate to oblong, 2–8.5 × 1–3 cm, base sagittate to cordate, margins entire, ciliate or eciliate, apex obtuse to acute, faces glabrous or densely appressed-pubescent, usually with retrorse prickles along midvein 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. |
capitate or paniclelike, uninterrupted, 5–15 × 4–10 mm; peduncle 10–80 mm, usually glabrous, sometimes with retrorse prickles proximally; ocreolae overlapping, margins eciliate. |
Pedicels | ascending, 1–4 mm. |
mostly 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. |
2–3 per ocreate fascicle; perianth white or greenish white, often tinged pink or red, sometimes entirely pink, glabrous, accrescent, not becoming blue and fleshy in fruit; tepals 5, connate 1/3–1/2 their length, broadly elliptic, 3–5 mm, apex obtuse; stamens 8, filaments distinct, free; anthers pink, ovate; styles 3, connate to 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 styles exserted, light or dark brown to black, 3-gonous, 2.5–4 × 1.8–2.5 mm, dull to shiny, smooth to minutely punctate. |
2n | = 44. |
= 40. |
Persicaria punctata |
Persicaria sagittata |
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Phenology | Flowering Jun–Nov. | Flowering Jun–Oct. |
Habitat | Shallow water, shores, marshes, floodplain forests | Moist shaded sites, meadows, pastures, fens, swamps, shorelines of ponds and streams |
Elevation | 0-1500 m [0-4900 ft] | 0-1000 m [0-3300 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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AL; AR; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; MB; NB; NF; NS; ON; PE; QC; e Asia
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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.) |
Persicaria sagittata is an extremely variable species. Achene and leaf characters have been used by some authors to separate North American and Asian populations, but these characters show weak geographic variation (C. W. Park 1988). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 586. | FNA vol. 5, p. 577. |
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 sagittatum, Polygonum sagittatum var. gracilentum, Tracaulon sagittatum, Truellum sagittatum |
Name authority | (Elliott) Small: Fl. S.E. U.S., 379. (1903) | (Linnaeus) H. Gross: Beih. Bot. Centralbl. 37(2): 113. (1919) |
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