Non-native Plants

European Marshwort

Apium nodiflorum

USDA symbol: APNO

perennial forb

Lower 48 states: non-native, naturalized

If you’ve ever wondered about those delicate, low-growing plants with tiny white flowers thriving in consistently soggy spots, you might be looking at European marshwort (Apium nodiflorum). This unassuming perennial has quietly made itself at home in wetland areas across several U.S. states, offering both opportunities and considerations for water ...

European Marshwort: A Wetland Ground Cover Worth Considering

If you’ve ever wondered about those delicate, low-growing plants with tiny white flowers thriving in consistently soggy spots, you might be looking at European marshwort (Apium nodiflorum). This unassuming perennial has quietly made itself at home in wetland areas across several U.S. states, offering both opportunities and considerations for water gardeners.

What is European Marshwort?

European marshwort is a perennial forb – basically a non-woody plant that comes back year after year. Originally from Europe, western Asia, and northern Africa, this plant has established itself as a naturalized species in parts of California, New Jersey, Pennsylvania, and South Carolina. You might also see it listed under its synonyms Cyclospermum nodiflorum or Helosciadium nodiflorum in older gardening references.

As its name suggests, this is definitely a moisture-loving plant. In fact, it’s classified as an obligate wetland species, meaning it almost always grows in wetland conditions – think permanently soggy soil or shallow standing water.

  • Species observed
  • No observations

Garden Appeal and Characteristics

European marshwort forms low-growing mats with delicate, divided foliage and produces clusters of tiny white flowers in umbrella-shaped arrangements. While it won’t win any awards for showstopping blooms, it has a subtle charm that works well in naturalized settings. The plant spreads via creeping stems, creating a living carpet in suitable conditions.

This ground-hugger typically grows in USDA hardiness zones 5-9, making it suitable for a wide range of climates as long as water requirements are met.

Where Does It Fit in Your Garden?

European marshwort shines in specific garden situations:

  • Bog gardens and rain gardens
  • Edges of ponds or water features
  • Consistently moist areas that challenge other plants
  • Naturalized wetland restoration projects
  • Areas with poor drainage where traditional ground covers struggle

Growing Conditions and Care

If you’re considering European marshwort, here’s what it needs to thrive:

  • Light: Full sun to partial shade
  • Soil: Consistently moist to saturated conditions – think swampy rather than well-draining
  • Water: Constant moisture is non-negotiable; this plant will struggle in anything less than consistently wet conditions
  • Maintenance: Minimal once established, though it may spread beyond desired areas in ideal conditions

Pollinator and Wildlife Benefits

The small white flowers attract various pollinators, particularly smaller species like flies and tiny bees. While not a pollinator powerhouse, every little bit helps in supporting local ecosystems.

Important Considerations

Since European marshwort is not native to North America, it’s worth considering native alternatives that provide similar benefits while supporting local wildlife more effectively. Native options for wet areas include:

  • Wild mint (Mentha arvensis)
  • Monkey flower species (Mimulus)
  • Native sedges (Carex species)
  • Watercress (Nasturtium officinale) – though this is also non-native

Before planting European marshwort, check with your local extension office about any regional concerns, as its status regarding invasiveness isn’t fully documented in all areas where it grows.

The Bottom Line

European marshwort can be a useful plant for challenging wet spots where few other options will survive. Its low-maintenance nature and ability to form attractive ground cover in boggy conditions make it worth considering for specific situations. However, given its non-native status, exploring native wetland plants first might better serve both your garden and local ecosystems. If you do choose to grow it, monitor its spread and be prepared to manage it if it becomes too enthusiastic in its new home.

Apium nodiflorum is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Apium nodiflorum is also known as:

Cyclospermum nodiflorum | USDA symbol: CYNO4
Helosciadium nodiflorum | USDA symbol: HENO3

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

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 care and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection can be if you don't have the right information. While tags on nursery plants 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. You might be surprised to learn that popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. The table below gives insight into the preferred growing conditions of this plant throughout its geographical distribution.

Region
Preferred Habitat

Arid West (AZ, CA, CO, ID, MT, NV, NM, OR, TX, UT, WA, WY)

Obligate Wetland

Atlantic and Gulf Coastal Plain (AL, AR, DC, DE, FL, GA, IL, KY, LA, MD, MS, MO, NC, NJ, OK, PA, SC, TN, TX, VA)

Obligate Wetland

Eastern Mountains and Piedmont (AL, AR, DC, DE, GA, IL, IN, KS, KY, MD, MO, NC, NJ, NY, OH, OK, PA, SC, TN, VA, WV)

Obligate Wetland

Northcentral & Northeast ()

Obligate Wetland
Wetland Glossary
Obligate Wetland
Facultative Wetland
Facultative
Facultative Upland
Obligate Upland
Almost always occurs in wetlands
Usually occurs in wetlands but may occur in non-wetlands
Can occur in wetlands and non-wetlands
Usually occurs in non-wetlands but may occur in wetlands
Almost never occurs in wetlands

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Rosidae
Order: Apiales
Family: Apiaceae Lindl. - Carrot family
Genus: Apium L. - celery

Species: Apium nodiflorum (L.) Lag. - European marshwort

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