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halberd-leaf smartweed, halberd-leaf tearthumb, renouée à feuilles d'arum

hairy smartweed

Habit Plants annual, 2–15 dm; roots also often arising from proximal nodes. Plants perennial, 3–9 dm; roots also often arising from proximal nodes; rhizomes present.
Stems

scandent, ribbed, glabrous;

prickles 0.5–1 mm.

decumbent to ascending or erect, branched, without noticeable ribs, brownish-hirsute on internodes.

Leaves

ocrea tan or brownish, cylindric, 8–15 mm, chartaceous, base inflated or not, with prickles, margins oblique, ciliate with bristles 0.5–2.5 mm, surface glabrous or appressed- to spreading-pubescent;

petiole 1–7 cm;

blade broadly hastate to hastate-cordate or triangular, (2–)6.5–13(–18) × (1–)6–11(–16) cm, base truncate to truncate-cordate, margins broadly hastate with lobes divergent, ciliate, sometimes also retrorsely prickly, apex acuminate, faces appressed-pubescent or, rarely, glabrous adaxially, stellate-pubescent or, rarely, glabrous abaxially, major veins often bearing prickles.

ocrea brown to reddish brown, cylindric, 6–12 mm, chartaceous, base sometimes inflated, margins truncate, eciliate or ciliate with bristles 4–7.5 mm, surface hirsute, not glandular-punctate;

petiole 0.1(–0.3) cm, hirsute, leaves sometimes sessile;

blade without dark triangular or lunate blotch adaxially, ovate to lanceolate, (2–)4–8 × (0.5–)1–2.5 cm, base rounded to cordate, margins strigose to hirsute, apex acute to acuminate, faces sparingly hirsute abaxially and adaxially, midvein usually hirsute abaxially.

Inflorescences

capitate or paniclelike, uninterrupted, 5–12 × 3–8 mm;

peduncle 10–80 mm, retrorsely prickly proximally, stellate-pubescent and stipitate-glandular distally, glands red or pink;

ocreolae usually overlapping, sometimes not overlapping proximally, margins eciliate or ciliate with bristles to 0.5 mm.

mostly terminal, erect, interrupted proximally, usually uninterrupted distally, 20–80 × 4–8 mm;

peduncle 30–60 mm, hirsute or, sometimes, nearly glabrous distally;

ocreolae overlapping distally, usually not overlapping proximally, margins ciliate with bristles 0.4–1.5(–2) mm.

Pedicels

mostly ascending, 2–3 mm.

ascending, 1–2 mm.

Flowers

2–4 per ocreate fascicle;

perianth pink or red, often whitish green proximally, glabrous, accrescent, not becoming blue and fleshy in fruit;

tepals 4, connate 1/3–1/2 their length, broadly elliptic, 5–6 mm, apex acute to obtuse;

stamens (6–)8, filaments distinct, free;

anthers pink, elliptic;

styles 2, distinct.

1–3 per ocreate fascicle, homostylous;

perianth white to pink, glabrous, not glandular-punctate, nonaccrescent;

tepals 5, connate in proximally 1/3, obovate, 1.5–2 mm, veins not prominent, not anchor-shaped, margins entire, apex obtuse to rounded;

stamens 5, included;

anthers red, elliptic to ovate;

styles 3, connate proximally.

Achenes

included, dark brown to black, biconvex, 3.5–6 × 3–4 mm, shiny, smooth.

included or apex exserted, dark brown to brownish black, 3-gonous, 2–2.5 × 1.3–1.8 mm, shiny, smooth.

2n

= 20.

Persicaria arifolia

Persicaria hirsuta

Phenology Flowering Jul–Oct. Flowering Jun–Oct.
Habitat Shaded swamps, ponds, tidal marshes along rivers, wet ravines in forests Sandy soils, open areas in savannahs, pond margins, ditches, often in shallow water
Elevation 0-600 m (0-2000 ft) 0-100 m (0-300 ft)
Distribution
from FNA
CT; DC; DE; GA; IL; IN; KY; LA; MA; MD; ME; MI; MN; MO; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WA; WI; WV; NB; NS; ON; PE; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA; MS; NC; SC
[BONAP county map]
Discussion

C. B. McDonald (1980) showed that Persicaria hirsuta is closely related to P. setacea and P. hydropiperoides. Hybrids between P. hirsuta and P. setacea have been produced experimentally but appear to be rare in the wild. Although geographically sympatric, the two species generally occupy different habitats. Experimental crosses between P. hirsuta and P. hydropiperoides were unsuccessful (McDonald).

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

Source FNA vol. 5, p. 577. FNA vol. 5, p. 587.
Parent taxa Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria
Sibling taxa
P. amphibia, 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. virginiana, P. wallichii
P. amphibia, P. arifolia, P. bicornis, P. bungeana, P. capitata, P. careyi, P. chinensis, P. glabra, 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 arifolium, Polygonum arifolium var. lentiforme, Polygonum arifolium var. pubescens, Polygonum sagittatum var. pubescens, Tracaulon arifolium, Truellum arifolium Polygonum hirsutum
Name authority (Linnaeus) Haraldson: Acta Univ. Upsal., Symb. Bot. Upsal. 22: 72. (1978) (Walter) Small: Fl. S.E. U.S., 379. (1903)
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