North America Native Plant

Alpine Flatsedge

Botanical name: Cyperus fauriei

USDA symbol: CYFA3

Life cycle: perennial

Habit: grass

Native status: Native to Hawaii  

Synonyms: Mariscus fauriei (Kük.) T. Koyama (MAFA7)   

Alpine Flatsedge: A Rare Hawaiian Native Worth Protecting Meet alpine flatsedge, a small but mighty sedge that calls Hawaii’s high elevations home. While you might not have heard of this unassuming grass-like plant, Cyperus fauriei plays a crucial role in Hawaii’s native ecosystems and represents one of the islands’ most ...

Rare plant alert!

Region: United States

Status: S1: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘

Region: United States

Alpine Flatsedge: A Rare Hawaiian Native Worth Protecting

Meet alpine flatsedge, a small but mighty sedge that calls Hawaii’s high elevations home. While you might not have heard of this unassuming grass-like plant, Cyperus fauriei plays a crucial role in Hawaii’s native ecosystems and represents one of the islands’ most endangered botanical treasures.

What Makes Alpine Flatsedge Special?

Alpine flatsedge is a perennial sedge that belongs to the Cyperaceae family, making it a relative of other grass-like plants rather than a true grass. This hardy little plant has adapted to Hawaii’s unique high-elevation environments, where cool temperatures and misty conditions create a very different world from the tropical beaches most people associate with the islands.

You might also see this plant referred to by its scientific synonym, Mariscus fauriei, in older botanical references.

Where Does It Grow?

Alpine flatsedge is found exclusively in Hawaii, making it what botanists call an endemic species. This means it evolved in isolation on the Hawaiian islands and exists nowhere else on Earth naturally.

A Plant in Crisis

Important Conservation Alert: Before we dive into growing this plant, there’s something crucial you need to know. Alpine flatsedge is critically endangered, with a Global Conservation Status of S1 and listed as Endangered. This means there are typically fewer than five known populations and fewer than 1,000 individual plants remaining in the wild.

If you’re interested in growing this rare beauty, please ensure you only obtain plants or seeds from reputable native plant societies, botanical gardens, or conservation organizations that can guarantee responsibly sourced, legally propagated material. Never collect from wild populations.

Growing Alpine Flatsedge: Not Your Average Garden Plant

Let’s be honest – alpine flatsedge isn’t going to win any beauty contests. This modest sedge produces small, brownish flower clusters and narrow leaves that won’t create dramatic focal points in your landscape. However, its value lies in its ecological importance and conservation significance rather than showy aesthetics.

Ideal Growing Conditions

Alpine flatsedge has very specific requirements that mirror its native high-elevation Hawaiian habitat:

  • Climate: Cool, moist conditions (USDA zones 9-11, specifically Hawaii’s climate)
  • Elevation: Prefers higher elevations with cooler temperatures
  • Moisture: Consistent moisture without waterlogging
  • Temperature: Cool conditions, unlike typical tropical Hawaiian plants

Best Garden Applications

This isn’t a plant for every garden. Alpine flatsedge works best in:

  • Native Hawaiian restoration projects
  • Specialized native plant collections
  • Conservation gardens
  • Educational botanical displays
  • High-elevation Hawaiian gardens

Care and Maintenance

Since specific care information for this rare plant is limited, work closely with native plant experts if you’re fortunate enough to grow it. General sedge care principles include maintaining consistent moisture and protecting from extreme temperature fluctuations.

Wildlife and Ecological Benefits

While we don’t have detailed information about specific wildlife that depends on alpine flatsedge, native sedges typically support local ecosystems in subtle but important ways. They may provide habitat for native insects and contribute to soil stability in their native habitats.

Should You Grow Alpine Flatsedge?

The answer depends on your location, expertise, and commitment to conservation. If you live in Hawaii and have experience with native plants, growing alpine flatsedge (from responsibly sourced material) could contribute to conservation efforts. However, this plant requires specialized conditions and won’t thrive in typical mainland gardens.

For most gardeners interested in supporting native ecosystems, focus on native plants from your own region. Every area has its own special sedges and grass-like plants that need our help and are better suited to local conditions.

The Bigger Picture

Alpine flatsedge reminds us that not every native plant needs to be a garden showstopper to be important. Sometimes the most valuable plants are the quiet, unassuming ones that hold ecosystems together. By learning about and protecting rare species like alpine flatsedge, we help preserve the incredible biodiversity that makes each region unique.

Whether you ever grow this plant or not, knowing about alpine flatsedge connects us to Hawaii’s unique natural heritage and the ongoing efforts to protect the islands’ irreplaceable endemic species.

Alpine 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 fauriei Kük. - alpine flatsedge

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