Persicaria punctata
Persicaria meisneriana
dotted knotweed, dotted smartweed, renouée ponctuée, water smartweed
Mexican tearthumb
ascending to erect, branched, without noticeable ribs, glabrous, glandular-punctate.
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.
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.
ascending, 1–4 mm.
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.
included or apex exserted, brownish black, usually 3-gonous, rarely biconvex, (1.8–)2.2–3.2 × 1.5–2.2 mm, shiny, smooth.
= 44.
Persicaria punctata
Persicaria meisneriana
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.)
Varieties 2 (1 in the flora).
Variety meisneriana has leaves with petioles 0.3–1 cm, blades prominently sagittate to hastate at bases, and ocreae usually moderately to densely pubescent. It is found only in South America (Argentina, Brazil, Paraguay).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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