Non-native Plants

Marsh Parsley

Cyclospermum leptophyllum

USDA symbol: CYLE7

annual forb

Hawaii: non-native, naturalized
Lower 48 states: non-native, naturalized
Pacific Basin excluding Hawaii: non-native, naturalized
Puerto Rico: non-native, naturalized
U.S. Virgin Islands: non-native, naturalized

If you’ve ever noticed a delicate, feathery plant with tiny white flowers popping up in disturbed areas or along pathways, you might have encountered marsh parsley (Cyclospermum leptophyllum). This diminutive annual herb has quietly made itself at home across much of the United States, despite being a South American native. ...

Marsh Parsley: A Delicate Non-Native with Mixed Garden Appeal

If you’ve ever noticed a delicate, feathery plant with tiny white flowers popping up in disturbed areas or along pathways, you might have encountered marsh parsley (Cyclospermum leptophyllum). This diminutive annual herb has quietly made itself at home across much of the United States, despite being a South American native. But should you welcome it into your garden? Let’s explore what makes this little plant tick.

What Is Marsh Parsley?

Marsh parsley goes by several names, including fine-leaved celery and fir-leaved celery, which give you a hint about its delicate, thread-like foliage. As an annual forb (that’s garden-speak for a non-woody plant that completes its life cycle in one year), it’s a member of the carrot family, though you won’t want to toss it in your salad.

This petite plant produces clusters of tiny white flowers arranged in umbrella-like formations called umbels—a classic characteristic of the carrot family. The finely divided leaves give the plant an almost ethereal, lacy appearance that some gardeners find charming.

Where Does Marsh Parsley Grow?

Originally from South America (specifically Argentina, Uruguay, and southern Brazil), marsh parsley has become quite the world traveler. In the United States, it has established populations across a surprisingly wide range of states, from Alabama and Arizona to Virginia and West Virginia, plus Hawaii, Puerto Rico, and the U.S. Virgin Islands.

  • Species observed
  • No observations

The plant shows remarkable adaptability to different moisture conditions. While it can handle both wet and dry sites in most regions, it tends to prefer drier conditions in the Western Mountains, Valleys, and Coast region.

Garden Appeal: The Good and the Challenging

Marsh parsley occupies an interesting niche in the garden world. On the positive side, its delicate texture and small white flowers can add a soft, naturalistic touch to cottage gardens or wildflower areas. The plant is remarkably low-maintenance, tolerating poor soils and requiring minimal care once established.

However, there’s a flip side to consider. This plant is a prolific self-seeder, which means it can pop up where you least expect it. Some gardeners appreciate this spontaneous quality, while others find it a bit too enthusiastic for their taste.

Growing Conditions and Care

If you decide to give marsh parsley a try, you’ll find it refreshingly undemanding:

  • Sunlight: Full sun to partial shade
  • Soil: Adapts to various soil types, including poor or disturbed soils
  • Water: Moderate moisture; quite drought-tolerant once established
  • USDA Zones: Primarily zones 8-11, but as an annual, it can grow in cooler zones from seed

Care requirements are minimal—perhaps too minimal for some gardeners’ liking. The plant readily self-seeds and can establish in areas with minimal soil preparation. If you’re trying to maintain a highly controlled garden design, you’ll need to stay on top of removing unwanted seedlings.

Wildlife and Pollinator Benefits

The small white flowers do attract tiny beneficial insects, though marsh parsley isn’t considered a major pollinator magnet compared to native alternatives. Its role in supporting local wildlife is relatively modest.

Should You Plant Marsh Parsley?

This is where things get interesting. While marsh parsley isn’t classified as invasive or noxious, it is a non-native species that has naturalized widely. For gardeners focused on supporting local ecosystems, there are compelling native alternatives to consider:

  • Native members of the carrot family like wild carrot (where appropriate)
  • Native annual wildflowers that provide similar delicate texture
  • Regional native plants that offer better wildlife support

If you appreciate marsh parsley’s low-maintenance nature and delicate appearance, and you’re comfortable with its self-seeding tendencies, it can work in naturalized areas or cottage-style gardens. Just be prepared to manage its enthusiasm for spreading, and consider whether native alternatives might better serve your local ecosystem.

The Bottom Line

Marsh parsley is one of those plants that falls into gardening’s gray area—not problematic enough to avoid entirely, but not outstanding enough to actively seek out. If it shows up in your garden naturally, you can appreciate its modest charms while keeping an eye on its spreading habits. If you’re planning a new planting, though, consider exploring native alternatives that offer similar aesthetic appeal with greater ecological benefits.

Whether you embrace it or gently discourage it, marsh parsley serves as a reminder that some of our most common garden companions are quiet immigrants, adapting and persisting in ways that continue to surprise us.

Cyclospermum leptophyllum 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. Cyclospermum leptophyllum is also known as:

Apium leptophyllum ex | USDA symbol: APLE2
Apium tenuifolium ex | USDA symbol: APTE
Cyclospermum ammi , non Sison ammi | USDA symbol: CYAM5

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)

Facultative Upland

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)

Facultative

Caribbean (PR, VI)

Facultative

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)

Facultative

Great Plains (CO, KS, MN, MT, NE, NM, ND, OK, SD, TX, WY)

Facultative

Hawaii ()

Facultative

Midwest (IL, IN, IA, KS, KY, MI, MN, MO, NE, ND, OK, OH, SD, WI)

Facultative

Western Mountains, Valleys, and Coast (AZ, CA, CO, ID, MT, NV, NM, OR, SD, UT, WA, WY)

Obligate Upland
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: Cyclospermum Lag. - marsh parsley

Species: Cyclospermum leptophyllum (Pers.) Sprague ex Britton & P. Wilson - marsh parsley

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