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false water pepper, false water-pepper smartweed, mild waterpepper, renouée faux-poivre-d'eau, swamp smartweed, water-pepper

jumpseed, renouée de virginie

Habit Plants perennial, 1.5–10 dm; roots also often arising from proximal nodes; rhizomes often present. Plants perennial, 4.5–6(–13) dm; rhizomatous.
Stems

decumbent to ascending, usually branched, without noticeable ribs, glabrous or obscurely strigose distally.

ribbed, glabrous or strigose.

Leaves

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.

ocrea brownish hyaline, cylindric, 10–20 mm, base inflated or not, margins truncate, ciliate with bristles 0.5–4 mm, surface strigose to tomentose;

petiole (0.1–)1–2 cm, leaves sometimes sessile;

blade 5–17.5 × 2–10 cm, apex acute to acuminate, faces pubescent abaxially, strigose and scabrous adaxially.

Inflorescences

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.

(50–)100–350 × 7–15 mm;

peduncle 10–70 mm, pubescent or glabrous distally;

ocreolae not overlapping, margins ciliate with bristles to 3 mm.

Pedicels

ascending, 1–1.5 mm.

ascending to spreading, 0.5–1 mm.

Flowers

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.

1–3 per ocreate fascicle;

perianth white, greenish white, or rarely pink, glabrous, accrescent;

tepals elliptic to obovate, 2.5–3.5 mm, apex acute to acuminate;

filaments distinct, outer ones sometimes adnate to perianth tube;

anthers yellow or pink, ovate;

styles distinct.

Achenes

included or apex exserted, brown to brownish black or black, 3-gonous, 1.5–3 × 1–2.3 mm, shiny, smooth.

included except for apex and styles, brown to dark brown, biconvex, 3.5–4 × 2–2.8 mm, dull to shiny, smooth to rugose.

2n

= 44.

Persicaria hydropiperoides

Persicaria virginiana

Phenology Flowering Jun–Nov. Flowering Jul–Oct.
Habitat Wet banks and clearings, shallow water, marshes, moist prairies, ditches Rich deciduous forests, floodplain forests, dry woodlands, thickets
Elevation 0-1500 m (0-4900 ft) 0-500 m (0-1600 ft)
Distribution
from FNA
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
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WI; WV; ON; QC; c Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Tension in the articulation of the pedicels is sufficient to throw mature achenes 3–4 m when the inflorescence is bumped, and the persistent, hooked styles aid in the dispersal of achenes in the fur of animals (H. S. Reed and I. Smoot 1906). A hot infusion of leaves with bark of honey-locust (Gleditsia triacanthos Linnaeus) was used by the Cherokee to treat whooping cough (D. E. Moerman 1998).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 585. FNA vol. 5, p. 575.
Parent taxa Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Tovara
Sibling taxa
P. amphibia, P. arifolia, P. bicornis, P. bungeana, P. capitata, P. careyi, P. chinensis, P. glabra, P. hirsuta, P. hydropiper, P. lapathifolia, P. longiseta, P. maculosa, P. meisneriana, P. minor, P. nepalensis, P. orientalis, P. pensylvanica, P. perfoliata, P. punctata, P. robustior, P. sagittata, P. setacea, P. virginiana, P. wallichii
P. amphibia, P. arifolia, P. bicornis, P. bungeana, P. capitata, P. careyi, P. chinensis, P. glabra, P. hirsuta, P. hydropiper, P. hydropiperoides, P. lapathifolia, P. longiseta, P. maculosa, P. meisneriana, P. minor, P. nepalensis, P. orientalis, P. pensylvanica, P. perfoliata, P. punctata, P. robustior, P. sagittata, P. setacea, P. wallichii
Synonyms 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 Polygonum virginianum, Antenoron virginianum, Tovara virginiana
Name authority (Michaux) Small: Fl. S.E. U.S., 378. (1903) (Linnaeus) Gaertner: Fruct. Sem. Pl. 2: 180. (1790)
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