Persicaria punctata |
Persicaria pensylvanica |
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dotted knotweed, dotted smartweed, renouée ponctuée, water smartweed |
Pennsylvania smartweed, pinkweed, renouée de pennsylvanie |
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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, 1–20 dm; roots also occasionally arising from basal nodes; rhizomes and stolons absent. |
Stems | ascending to erect, branched, without noticeable ribs, glabrous, glandular-punctate. |
ascending to erect, simple or branched, ribbed, glabrous or appressed-pubescent distally, eglandular or stipitate-glandular 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 brownish, cylindric, 5–20 mm, chartaceous, base inflated, margins truncate, eciliate or ciliate with bristles to 0.5 mm, surface glabrous or appressed-pubescent, eglandular; petiole 0.1–2(–3) cm, glabrous or appressed-pubescent; blade sometimes with dark triangular or lunate blotch adaxially, narrowly to broadly lanceolate, 4–17(–23) × (0.5–)1–4.8 cm, base tapered to cuneate, margins antrorsely scabrous, apex acuminate, faces glabrous or appressed-pubescent, eglandular or glandular-punctate abaxially and occasionally 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. |
terminal and axillary, erect or rarely nodding, uninterrupted, 5–50 × 5–15 mm; peduncle 10–55(–70) mm, glabrous or pubescent, usually stipitate-glandular; ocreolae overlapping, margins eciliate or ciliate with bristles to 0.5 mm. |
Pedicels | ascending, 1–4 mm. |
ascending, 1.5–4.5 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. |
2–14 per ocreate fascicle, homostylous; perianth greenish white to roseate, glabrous, not glandular-punctate, accrescent; tepals 5, connate ca. 1/4–1/3 their length, obovate to elliptic, 2.5–5 mm, veins prominent, not anchor-shaped, margins entire, apex obtuse to rounded; stamens 6–8, included; anthers yellow, pink, or red, elliptic; styles 2(–3), connate at bases. |
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 black, discoid or, rarely, 3-gonous, without central hump on 1 side, 2.1–3.4 × 1.8–3 mm, shiny, smooth. |
2n | = 44. |
= 88. |
Persicaria punctata |
Persicaria pensylvanica |
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Phenology | Flowering Jun–Nov. | Flowering May–Dec. |
Habitat | Shallow water, shores, marshes, floodplain forests | Moist, disturbed places, ditches, riverbanks, cultivated fields, shorelines of ponds and reservoirs |
Elevation | 0-1500 m (0-4900 ft) | 0-1800 m (0-5900 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; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; PA; RI; SC; SD; TN; TX; UT; VA; VT; WI; WV; WY; NB; NF; NS; ON; QC; South America (Ecuador); Europe (England, Spain)
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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 pensylvanica is a morphologically variable allotetraploid, with P. lapathifolia probably one of the parents (L. L. Consaul et al. 1991). Three or four varieties (under Polygonum) often have been accepted in North American floras; the characters on which these are based vary greatly within and among populations. J. W. Taylor-Lehman (1987) concluded that Polygonum pensylvanicum is best treated as a polymorphic species without infraspecific taxa, based on specimens primarily from Ohio. The heterostylous Persicaria bicornis often is included in P. pensylvanica. A single chromosome count of 2n = 22 reported by Á. Löve and D. Löve (1982), which could not be confirmed by Consaul et al. because the voucher could not be found, is excluded. Flowers with three styles and trigonous achenes are produced; they are exceedingly rare and probably mostly overlooked. Several Native American tribes prepared infusions and decoctions from P. pensylvanica, which they used as drugs for humans and horses (D. E. Moerman 1998). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 586. | FNA vol. 5, p. 588. |
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 pensylvanicum, P. mississippiensis, P. pensylvanica var. dura, Polygonum omissum, Polygonum pensylvanicum var. durum, Polygonum pensylvanicum var. eglandulosum, Polygonum pensylvanicum var. laevigatum, Polygonum pensylvanicum var. nesophilum, Polygonum pensylvanicum var. rosiflorum |
Name authority | (Elliott) Small: Fl. S.E. U.S., 379. (1903) | (Linnaeus) M. Gómez: Anales Inst. Segunda Enseñ. 2: 278. (1896) |
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