North America Native Plant

Buttonbush Flatsedge

Botanical name: Cyperus cephalanthus

USDA symbol: CYCE

Life cycle: perennial

Habit: grass

Native status: Native to the lower 48 states  

Buttonbush Flatsedge: A Rare Native Sedge Worth Growing Meet the buttonbush flatsedge (Cyperus cephalanthus), a humble yet important native sedge that deserves a spot in your wetland garden. While it may not win any beauty contests, this unassuming perennial plays a vital role in supporting our native ecosystems—and it’s actually ...

Rare plant alert!

Region: Conservation status by state

Status: S3?Q: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Uncertain taxonomy: ⚘ 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 ⚘

Buttonbush Flatsedge: A Rare Native Sedge Worth Growing

Meet the buttonbush flatsedge (Cyperus cephalanthus), a humble yet important native sedge that deserves a spot in your wetland garden. While it may not win any beauty contests, this unassuming perennial plays a vital role in supporting our native ecosystems—and it’s actually quite rare, making it all the more special to cultivate.

Where Does Buttonbush Flatsedge Come From?

This native gem calls the coastal plains of Louisiana and Texas home, where it thrives in the region’s wet, marshy conditions. Its limited geographic range makes it a true regional specialty—think of it as the local craft beer of the sedge world!

Why Grow This Rare Beauty?

Here’s where things get interesting: buttonbush flatsedge has a Global Conservation Status of S3?Q, which means its population status is somewhat uncertain but potentially vulnerable. By growing this species in your garden, you’re essentially becoming a conservation hero, helping to preserve a piece of our natural heritage right in your backyard.

As a member of the sedge family (Cyperaceae), this grass-like perennial brings authentic regional character to naturalistic landscapes. It’s perfect for gardeners who want to create habitat that truly reflects their local ecosystem.

What Does It Look Like?

Don’t expect flashy flowers or dramatic foliage—buttonbush flatsedge is all about subtle charm. This clumping perennial has a grass-like appearance with narrow leaves and produces small, inconspicuous flower clusters. It’s the kind of plant that blends seamlessly into natural settings, creating texture and movement without stealing the spotlight.

Perfect Garden Spots for Buttonbush Flatsedge

This sedge is practically begging to be planted in:

  • Rain gardens and bioswales
  • Bog gardens and wetland plantings
  • Natural areas needing erosion control
  • Restoration projects in coastal regions
  • Wildlife gardens focused on native habitat

Growing Conditions That Make It Happy

Buttonbush flatsedge is surprisingly easy to please once you understand its preferences:

  • Moisture: Loves moist to wet soils—think swamp, not desert
  • Light: Full sun to partial shade (quite flexible!)
  • Soil: Tolerates various soil types as long as they stay moist
  • Climate: Thrives in USDA hardiness zones 8-10

Planting and Care Tips

The good news? Once established, buttonbush flatsedge is refreshingly low-maintenance. Here’s how to set it up for success:

  • Plant in consistently moist to wet locations
  • Ensure good drainage flow (it likes wet feet, not stagnant water)
  • Mulch around plants to retain moisture
  • Be patient—it may take a season to fully establish
  • Minimal fertilizing needed; it’s adapted to natural wetland conditions

A Word About Responsible Sourcing

Here’s the important part: given its rare status, please source buttonbush flatsedge only from reputable native plant nurseries that propagate their own stock. Never collect from wild populations—we want to help this species thrive, not put additional pressure on natural stands.

Wildlife and Ecosystem Benefits

While buttonbush flatsedge may be wind-pollinated (so it won’t attract butterflies like a wildflower), it still provides valuable ecosystem services. Its root system helps prevent erosion, and it contributes to the complex web of life in wetland habitats. Native sedges like this one support various insects and provide nesting materials for birds.

The Bottom Line

Buttonbush flatsedge isn’t for every garden, but if you have a wet spot that needs a native touch, this rare sedge could be your perfect match. You’ll be supporting biodiversity conservation while adding authentic regional character to your landscape. Just remember to source responsibly and give it the moisture it craves. Sometimes the most meaningful plants are the quiet ones that do their job without fanfare—and buttonbush flatsedge does exactly that.

Buttonbush Flatsedge

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

Cyperaceae Juss. - Sedge family

Genus

Cyperus L. - flatsedge

Species

Cyperus cephalanthus Torr. & Hook. - buttonbush flatsedge

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