Knotweed Family (Polygonaceae). Pennsylvania smartweed is an annual herb that has small, five-parted pink or rose colored flowers on a short spike. It grows 2 to 4(6) feet high. The flowering branches have stalked glands. The stems have a reddish color and swollen nodes. The alternate leaves have sheaths extending around the stems. The seeds are black, shiny, flattened, and almost round. There are approximately 62,000 seeds per pound.

Persicaria mississippiensis (Stanford) Small:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Polygonum pensylvanicum var. nesophilum Fernald:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Polygonum pensylvanicum var. durum Stanford:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Polygonum pensylvanicum var. rosiflorum Norton:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Polygonum pensylvanicum var. laevigatum Fernald:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Polygonum pensylvanicum var. eglandulosum Myers:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Polygonum pensylvanicum L.:
Canada (North America)
Ecuador (South America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Persicaria pensylvanica (L.) M. Gómez:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

N.B., Nfld. and Labr. (Nfld.), N.S., Ont., Que.; Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., W.Va., Wis., Wyo.; South America (Ecuador); Europe (England, Spain).

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Pennsylvania smartweed is adapted to soils of all drainage classes except droughty soils. It commonly occurs on mudflats of fresh water to moderately brackish areas throughout the Northeast.

Pennsylvania smartweed is distributed throughout the entire Unites States, excluding a few northwestern states. For a current distribution map, please consult the Plant Profile page for this species on the PLANTS Web site.

Plants annual, 1-20 dm; roots also occasionally arising from basal nodes; rhizomes and stolons absent. Stems ascending to erect, simple or branched, ribbed, glabrous or appressed-pubescent distally, eglandular or stipitate-glandular distally. Leaves: 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 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, 1.5-4.5 mm. Flowers 2-14 per ocreate fascicle, homostylous; perianth greenish white to roseate, glabrous, not glandular-punctate, accrescent; tepals 5, connate ca. 1/ 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, 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 = 88.

Polygonum pensylvanicum Linnaeus, Sp. Pl. 1: 362. 1753; Persicaria mississippiensis (Stanford) Small; P. pensylvanica var. dura (Stanford) C. F. Reed; Polygonum omissum Greene; P. pensylvanicum var. durum Stanford; P. pensylvanicum var. eglandulosum Myers; P. pensylvanicum var. laevigatum Fernald; P. pensylvanicum var. nesophilum Fernald; P. pensylvanicum var. rosiflorum Norton

Isotype for Polygonum mississippiense Stanford
Catalog Number: US 383581
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Card file verified by examination of original publication
Preparation: Pressed specimen
Collector(s): S. M. Tracy & F. E. Lloyd
Year Collected: 1900
Locality: Long Beach., Harrison, Mississippi, United States, North America

Isotype for Polygonum mississippiense var. interius Stanford
Catalog Number: US 313713
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Preparation: Pressed specimen
Collector(s): L. A. Blankinship
Year Collected: 1896
Locality: Huntsville., Kingfisher, Oklahoma, United States, North America

Moist, disturbed places, ditches, riverbanks, cultivated fields, shorelines of ponds and reservoirs; 0-1800m.

A seedbed that reduces most weed competition and permits smartweed to be covered by one inch of soil depth is usually sufficient. Drop water quickly and broadcast seed on top of wet ground in mudflats or drawdown areas. Seed after the last killing frost in the spring. Smartweed may be seeded later so that seed maturity coincides with the arrival of migratory birds. Seeds are generally broadcast at a rate of 10-15 pounds per acre.

Flowering May-Dec.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

No varieties exist, but common seed may be obtained through wildlife and game food seed dealers.

As an upland wildlife food source, plant either in pure stands or in mixtures with other suitable and adapted species. For waterfowl food, draw down water where necessary shortly before planting. Do not re-flood until plants are at least 6 inches in height. Flood the area to a depth of 12-18 inches during the migratory season. Re-plant annually to assure a uniform stand. A light harrowing is recommended to encourage natural re-establishment of stands.

This plant is an excellent wildlife food plant, especially for waterfowl. Twenty species of ducks, geese, bobwhites, mourning doves, ring-necked pheasants, and four species of rails, as well as 30 nongame birds, eat the seeds. Dense stands provide cover for young waterfowl, marsh birds, and wintering pheasants. Plants and/or seeds are eaten by white-footed mice, muskrat, raccoons, and fox squirrels.

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).

Comments: Varieties not recogized within the species Polygonum pensylvanicum by Kartesz (1999).