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

Carey's smartweed, renouée de Carey

Habit Plants perennial, 1.5–10 dm; roots also often arising from proximal nodes; rhizomes often present. Plants annual, 3–15(–20) dm; roots also rarely arising from proximal nodes; rhizomes and stolons absent.
Stems

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

erect, branched distally, ribbed distally, hirsute proximally, stipitate-glandular distally, usually smooth proximally.

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 to reddish brown, cylindric, 8–20 mm, chartaceous, base inflated or not, margins truncate, ciliate with bristles 2–7 mm, surface strigose to hirsute, not glandular-punctate, rarely stipitate-glandular;

petiole (0.1–)0.5–1.5 cm, hirsute, leaves sometimes sessile;

blade without dark triangular or lunate blotch adaxially, narrowly lanceolate, 6–18 × 1–3.5 cm, base tapering, margins antrorsely strigose, apex acuminate to attenuate, faces sparingly hirsute abaxially and adaxially, veins often hirsute, sometimes stipitate-glandular.

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.

terminal and axillary, nodding or drooping, usually interrupted, 10–100 × 5–10 mm;

peduncle 20–50 mm, stipitate-glandular;

ocreolae overlapping or not overlapping proximally, margins eciliate or ciliate with bristles to 1.3 mm.

Pedicels

ascending, 1–1.5 mm.

ascending to spreading, 1–4 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–)2–8 per ocreate fascicle, homostylous;

perianth roseate or purple, glabrous, not glandular-punctate, scarcely accrescent;

tepals 5, connate in proximal 1/3, obovate, 2.4–3.2 mm, veins prominent or not, not anchor-shaped, margins entire, apex obtuse to rounded;

stamens 5 (or 8), included;

anthers pink, elliptic;

styles 2, connate to middle.

Achenes

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

included, dark brown to black, biconvex, 1.8–2.5 × 1.5–2 mm, shiny, smooth.

Persicaria hydropiperoides

Persicaria careyi

Phenology Flowering Jun–Nov. Flowering Jul–Oct.
Habitat Wet banks and clearings, shallow water, marshes, moist prairies, ditches Low thickets, swamps, bogs, moist shorelines, clearings, recent burns, cultivated ground
Elevation 0-1500 m (0-4900 ft) 0-300 m (0-1000 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
CT; DE; FL; IL; IN; KY; MA; MD; ME; MI; MN; NH; NJ; NY; OH; PA; RI; VA; VT; WI; NB; ON; QC
[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.)

An infusion made from entire plants of Persicaria careyi was used by the Potawatomi as a cold remedy and febrifuge (D. E. Moerman 1998).

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

Source FNA vol. 5, p. 585. FNA vol. 5, p. 592.
Parent taxa Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria
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. 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. virginiana, 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 careyi
Name authority (Michaux) Small: Fl. S.E. U.S., 378. (1903) (Olney) Greene: Leafl. Bot. Observ. Crit. 1: 24. (1904)
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