North America Native Plant

Simpson’s Cupgrass

Botanical name: Eriochloa michauxii var. simpsonii

USDA symbol: ERMIS

Life cycle: annual

Habit: grass

Native status: Native to the lower 48 states  

Simpson’s Cupgrass: A Rare Florida Native Worth Protecting Meet Simpson’s cupgrass (Eriochloa michauxii var. simpsonii), a little-known native grass that’s quietly holding down the fort in Florida’s diverse ecosystem. While it might not be the showiest plant in your garden, this humble grass carries significant ecological importance and deserves our ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4TH: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Simpson’s Cupgrass: A Rare Florida Native Worth Protecting

Meet Simpson’s cupgrass (Eriochloa michauxii var. simpsonii), a little-known native grass that’s quietly holding down the fort in Florida’s diverse ecosystem. While it might not be the showiest plant in your garden, this humble grass carries significant ecological importance and deserves our attention—and protection.

What Makes Simpson’s Cupgrass Special?

Simpson’s cupgrass is a native grass species that belongs to the Poaceae family, making it a true grass rather than a grass-like impostor. This annual to perennial plant is endemic to Florida, meaning it’s found nowhere else in the world naturally. That’s pretty special when you think about it—Florida has its very own exclusive grass!

Where Does It Call Home?

This grass is a Florida exclusive, naturally occurring only within the Sunshine State’s borders. While it’s native to the lower 48 states as a whole, its distribution is remarkably limited to Florida’s unique ecosystems.

The Rarity Factor: Handle with Care

Here’s where things get serious—Simpson’s cupgrass has a Global Conservation Status of S3S4TH, which indicates it’s considered rare and potentially vulnerable. This means we need to be thoughtful about how we approach growing this plant.

If you’re interested in cultivating Simpson’s cupgrass, please ensure you source it responsibly. This means:

  • Only purchasing from reputable native plant nurseries
  • Never collecting from wild populations
  • Choosing nursery-propagated plants over wild-harvested specimens
  • Supporting conservation efforts by growing native plants responsibly

Should You Grow Simpson’s Cupgrass?

The short answer is: maybe, but with caution. If you’re a dedicated native plant enthusiast in Florida who wants to support local biodiversity, Simpson’s cupgrass could be a meaningful addition to your landscape. However, given its rarity, this isn’t a plant for casual gardeners.

Consider growing Simpson’s cupgrass if you:

  • Are passionate about preserving Florida’s native flora
  • Have experience growing native grasses
  • Can source plants responsibly
  • Want to contribute to conservation efforts

Growing Considerations

Unfortunately, detailed growing information for this rare variety is limited due to its specialized nature. As a native Florida grass, it’s likely adapted to the state’s warm, humid climate and may prefer the growing conditions typical of its natural habitat.

Since specific care instructions are scarce, your best bet is to:

  • Consult with local native plant societies
  • Contact Florida botanical gardens or extension services
  • Mimic the natural conditions where the plant typically grows
  • Start small and observe how the plant responds to your specific site

The Bigger Picture

While Simpson’s cupgrass might not be the easiest or most readily available native plant to grow, it represents something important: Florida’s unique botanical heritage. By choosing to grow rare native plants responsibly, we become part of a larger conservation story.

If you’re new to native gardening or looking for easier Florida native grasses to start with, consider more common species first. Once you’ve gained experience and confidence with native plants, you might be ready to take on the responsibility of growing something as special as Simpson’s cupgrass.

Remember, every native plant we grow—whether common or rare—is a small victory for biodiversity and a step toward creating more sustainable, ecologically valuable landscapes.

Simpson’s Cupgrass

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Commelinidae

Order

Cyperales

Family

Poaceae Barnhart - Grass family

Genus

Eriochloa Kunth - cupgrass

Species

Eriochloa michauxii (Poir.) Hitchc. - longleaf cupgrass

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