North America Native Plant

Oahu Sedge

Botanical name: Carex wahuensis wahuensis

USDA symbol: CAWAW

Life cycle: perennial

Habit: grass

Native status: Native to Hawaii  

Oahu Sedge: A Rare Hawaiian Treasure for Your Garden Meet the Oahu sedge (Carex wahuensis wahuensis), a special little grass-like plant that’s as unique as the beautiful Hawaiian island it calls home. This perennial sedge might not be the flashiest plant in the garden center, but it carries the distinct ...

Rare plant alert!

Region: Conservation status by state

Status: S3T1T3: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is 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) ⚘ 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 ⚘ Subspecies or variety is 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. ⚘

Oahu Sedge: A Rare Hawaiian Treasure for Your Garden

Meet the Oahu sedge (Carex wahuensis wahuensis), a special little grass-like plant that’s as unique as the beautiful Hawaiian island it calls home. This perennial sedge might not be the flashiest plant in the garden center, but it carries the distinct honor of being a true Hawaiian native – something that’s becoming increasingly rare in today’s world.

Where Does Oahu Sedge Come From?

As its name suggests, Oahu sedge is native exclusively to Hawaii, specifically the island of Oahu. This makes it part of Hawaii’s precious endemic flora – plants that evolved nowhere else on Earth. It’s like having a piece of authentic Hawaiian heritage right in your landscape!

A Word of Caution: This Plant is Rare

Here’s something important every gardener should know: Oahu sedge has a Global Conservation Status of S3T1T3, which indicates this species faces conservation challenges. What does this mean for you as a gardener? While we absolutely encourage supporting native Hawaiian plants, if you’re interested in growing Oahu sedge, please make sure you source it responsibly from reputable native plant nurseries that propagate their own stock rather than wild-collecting.

What Makes Oahu Sedge Special?

Like other members of the sedge family, Oahu sedge is a grass-like perennial that brings a naturalistic, textural element to gardens. Sedges are fantastic plants because they:

  • Add movement and texture with their slender, arching leaves
  • Provide year-round interest as perennials
  • Often serve as important habitat for native wildlife
  • Require less maintenance than traditional lawn grasses

Growing Oahu Sedge: What We Know

Because Oahu sedge is such a specialized native plant, specific cultivation information is limited. However, we can make some educated guesses based on its Hawaiian origins and sedge family characteristics:

  • It likely prefers the warm, tropical conditions found in Hawaii
  • As a sedge, it probably appreciates consistent moisture
  • It would thrive in naturalistic or native Hawaiian landscape designs
  • Like most sedges, it’s probably relatively low-maintenance once established

Is Oahu Sedge Right for Your Garden?

This plant would be perfect for you if:

  • You live in Hawaii and want to support native species
  • You’re creating a native Hawaiian landscape
  • You love unique, conversation-starter plants
  • You want to contribute to conservation efforts

However, if you live outside of Hawaii, this plant likely won’t be suitable for your climate, and you’d be better served choosing sedges native to your specific region.

The Bottom Line

Oahu sedge represents something special – a connection to Hawaii’s unique natural heritage. While it may not be the easiest plant to find or grow, supporting rare native species like this one helps preserve biodiversity for future generations. If you’re in Hawaii and can source it responsibly, consider giving this humble sedge a place in your native garden. Just remember: with great plants comes great responsibility!

For those outside Hawaii, consider this an inspiration to seek out the rare native sedges in your own area – every region has its own botanical treasures waiting to be discovered and celebrated.

Oahu Sedge

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

Carex L. - sedge

Species

Carex wahuensis C.A. Mey. - Oahu sedge

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