Polygonum pensylvanicum L.

vernacular Pennsylvania smartweed — species · Polygonaceae

USDA: POPE2
GBIF: 7614480
Rank: species

Pennsylvania smartweed (Polygonum pensylvanicum) — Platephotograph · lynneropCC BY-NC source · iNaturalist ↗

§2Habit & range

Growth habit: Forb/herb
Duration: Annual
Group: Dicot
Family: Polygonaceae Juss.
Genus: Polygonum

§2a

Native status, by region

AK Alaska Native
CAN Canada Native
L48 Lower 48 States Native

§2b

County-level range

· 7 counties across 2 states/territories

Legend Native · 7 Introduced · 0 Both · 0 Hover a county for detail.

§3Cultivation specs · USDA

Recorded by the USDA Plant Materials Program.

§3a

Tolerances

Drought: Medium
Shade: High
Moisture use: Medium
Fire: High
Salinity: Low
Anaerobic: Medium
CaCO₃: Medium
Hedging: None

§3b

Climate & soil

Cold tolerance: 32 °F minimum
Frost-free days: 95 min.
Precipitation: 12–60 in/yr
pH range: 4–8.5
Root depth: 14 in min.
Fertility need: Medium
Soil texture: coarse, medium, fine

§3c

Form & growth

Growth form: Single Crown
Growth rate: Moderate
Mature height: 3.9 ft
Foliage texture: Medium
Foliage colour: Green
Porosity (summer): Moderate
Porosity (winter): Porous
Flower colour: Red
Fruit colour: Black
Fire resistant: No
N fixation: None
Toxicity: None

§3d

Reproduction

Bloom period: Spring
Seed abundance: Medium
Seed begins: Spring
Seed ends: Fall
Spread rate: Rapid
Stratify: No
Seeds / lb: 126,111
Propagation: seed

§3e

Use & availability

Commercial availability: Routinely Available
Nursery stock: No
Graze palatability: Low
Palatable, human: No
Lumber: No
Christmas tree: No

§4Counties, by state

Recorded in 7 counties across 2 states/territories.

Montana view state ↗ 2 N ▾

Rhode Island view state ↗ 5 N ▾

§5Sources & provenance

USDA PLANTS

Symbol, taxonomy, distribution, cultivation specs, native status. Public domain.

plants.usda.gov/POPE2 ↗

GBIF Backbone

Canonical taxonomic identity, synonym resolution, cross-refs. CC0.

gbif.org/species/7614480 ↗

Record version

Cached and built locally. Source version on this record:

usda-plants-mt-2026-05-25

fetched 2026-05-25T18:27:19Z