North America Native Plant

Field Smartweed

Botanical name: Polygonum segetum

USDA symbol: POSE4

Life cycle: perennial

Habit: forb

Native status: Native to Puerto Rico  

Synonyms: Persicaria segeta (Kunth) Small (PESE17)   

Field Smartweed: A Native Puerto Rican Wetland Plant Worth Knowing If you’re gardening in Puerto Rico or simply curious about native Caribbean flora, field smartweed (Polygonum segetum) might have caught your attention. This perennial forb represents an interesting piece of Puerto Rico’s natural wetland heritage, though it’s admittedly not the ...

Field Smartweed: A Native Puerto Rican Wetland Plant Worth Knowing

If you’re gardening in Puerto Rico or simply curious about native Caribbean flora, field smartweed (Polygonum segetum) might have caught your attention. This perennial forb represents an interesting piece of Puerto Rico’s natural wetland heritage, though it’s admittedly not the most well-documented plant in the gardening world.

What Exactly Is Field Smartweed?

Field smartweed belongs to the smartweed family and goes by the scientific name Polygonum segetum, though you might also see it listed as Persicaria segeta in some botanical references. As a forb, it’s essentially an herbaceous plant—think of it as a non-woody perennial that comes back year after year without developing thick, tree-like stems.

Where Does It Call Home?

This plant is a true Puerto Rican native, naturally occurring throughout the island. Its geographic distribution is quite limited, making it a special representative of Caribbean flora that you won’t find naturally growing in the continental United States.

The Wetland Connection

Here’s where field smartweed gets really interesting—it’s what botanists call an obligate wetland species. This fancy term simply means the plant almost always lives in wet conditions. If you spot field smartweed growing somewhere, you can be pretty confident there’s consistent moisture in that area.

Should You Grow Field Smartweed?

The honest answer is: it’s complicated. While field smartweed has the appeal of being a true Puerto Rican native, there’s limited information available about its cultivation requirements, growth habits, or potential garden benefits. Here’s what we do know:

  • It’s a perennial, so it should return each year
  • It requires consistently wet conditions
  • It’s native to Puerto Rico, making it ecologically appropriate for the region
  • Its growth form and mature size aren’t well documented

Growing Conditions and Care

Based on its obligate wetland status, field smartweed would likely thrive in:

  • Rain gardens or bioswales
  • Pond edges or water garden margins
  • Areas with consistent moisture or seasonal flooding
  • Naturalized wetland restoration projects

Unfortunately, specific details about soil preferences, sun requirements, or USDA hardiness zones aren’t readily available for this particular species.

The Bottom Line

Field smartweed represents an intriguing piece of Puerto Rico’s native plant puzzle, especially for gardeners interested in wetland plants or ecological restoration. However, the limited cultivation information means you’d be somewhat pioneering if you choose to grow it.

If you’re drawn to native Puerto Rican plants for wet areas, you might consider researching other well-documented native wetland species that could provide similar ecological benefits with more reliable growing information. That said, if you’re working on a wetland restoration project or have the perfect soggy spot that needs a true local native, field smartweed could be worth investigating further through local botanical organizations or native plant societies in Puerto Rico.

The key is ensuring any plants you acquire are responsibly sourced and that you’re prepared for some trial and error in determining the best growing conditions for this somewhat mysterious native.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Caribbean

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Field Smartweed

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Caryophyllidae

Order

Polygonales

Family

Polygonaceae Juss. - Buckwheat family

Genus

Polygonum L. - knotweed

Species

Polygonum segetum Kunth - field smartweed

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA