Native Plants

Asian Watermeal

Wolffia globosa

USDA symbol: WOGL3

perennial forb

Hawaii: non-native, naturalized
Lower 48 states: native

Meet Asian watermeal (Wolffia globosa), quite possibly the most unusual plant you’ll ever encounter in your gardening journey. This microscopic marvel holds the impressive title of being one of the world’s smallest flowering plants, measuring just about 1 millimeter across – smaller than a pinhead! If you’re looking to add ...

Asian Watermeal: The World’s Tiniest Flowering Plant for Your Water Garden

Meet Asian watermeal (Wolffia globosa), quite possibly the most unusual plant you’ll ever encounter in your gardening journey. This microscopic marvel holds the impressive title of being one of the world’s smallest flowering plants, measuring just about 1 millimeter across – smaller than a pinhead! If you’re looking to add something truly unique to your water garden, this floating wonder might just capture your imagination.

What Exactly Is Asian Watermeal?

Asian watermeal is a perennial aquatic plant that belongs to the duckweed family. Despite its common name, it has nothing to do with actual meal – the name comes from its tiny, grain-like appearance floating on water surfaces. Each individual plant looks like a microscopic green dot, but when they multiply (and trust us, they do!), they create dense, carpet-like mats across the water surface.

This little botanical curiosity is technically classified as a forb – a non-woody vascular plant that lacks significant woody tissue above ground. But don’t let the technical classification fool you; there’s nothing ordinary about this extraordinary plant.

Where Does Asian Watermeal Come From?

Originally native to Asia, particularly Southeast Asia, Asian watermeal has made itself at home in several U.S. states including California, Florida, Hawaii, and Kentucky. It’s considered non-native to the continental United States but has naturalized in these areas, reproducing without human intervention and persisting in suitable habitats.

  • Species observed
  • No observations

Should You Grow Asian Watermeal in Your Garden?

The answer depends entirely on what you’re hoping to achieve with your water feature. Here’s what you need to consider:

The Good: Asian watermeal is absolutely fascinating from a botanical perspective. It’s perfect for aquarium enthusiasts, water garden hobbyists, or anyone who loves unusual plants. It provides natural water surface coverage and can help reduce algae by competing for nutrients.

The Not-So-Good: This plant is a prolific reproducer. Under ideal conditions, it can quickly cover entire water surfaces, potentially overwhelming smaller water features. Its tiny size also means it offers minimal aesthetic impact compared to larger aquatic plants.

Native Alternatives: If you’re looking to support local ecosystems, consider native alternatives like American lotus, spatterdock, or native duckweed species that provide similar water coverage while supporting local wildlife.

Growing Conditions and Care

Asian watermeal has very specific requirements that make it suitable only for certain situations:

  • Water Requirements: Needs still or very slow-moving freshwater
  • Climate: Thrives in USDA hardiness zones 9-11, requiring consistently warm water temperatures
  • Nutrients: Prefers nutrient-rich water conditions
  • Sunlight: Does well in both full sun and partial shade

Planting and Maintenance Tips

Growing Asian watermeal is surprisingly simple, though controlling it can be the bigger challenge:

  • Introduction: Simply place the plants directly into your water feature – no soil required!
  • Feeding: May benefit from aquatic plant fertilizer, especially in nutrient-poor water
  • Temperature: Keep water temperatures warm; the plant won’t survive freezing conditions
  • Population Control: Regular harvesting may be necessary to prevent complete surface coverage
  • Winter Care: In cooler climates, bring indoors or maintain in heated water features

Wildlife and Ecological Benefits

Due to its extremely small size and aquatic nature, Asian watermeal provides limited benefits for pollinators and larger wildlife. However, it can serve as food for waterfowl and provides some habitat for aquatic microorganisms.

The Bottom Line

Asian watermeal is definitely a conversation starter and a unique addition to specialized aquatic gardens or aquarium systems. While it won’t provide the dramatic visual impact of larger water plants, it offers the novelty of growing one of the world’s smallest flowering plants. Just be prepared for its enthusiastic growth habits and consider whether native alternatives might better serve both your garden goals and local ecosystem needs.

Whether you decide to grow this microscopic marvel or opt for native alternatives, remember that the best garden choices are always the ones that align with your gardening goals, local conditions, and ecological values.

Wolffia globosa 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. Wolffia globosa is also known as:

Wolffia cylindracea | USDA symbol: WOCY

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

Hawaii ()

Obligate Wetland

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

Obligate Wetland

Northcentral & Northeast ()

Obligate Wetland

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

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: Monocot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Liliopsida - Monocotyledons
Subclass: Arecidae
Order: Arales
Family: Lemnaceae Martinov - Duckweed family
Genus: Wolffia Horkel ex Schleid. - watermeal

Species: Wolffia globosa (Roxb.) Hartog & Plas - Asian watermeal

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