North America Native Plant

Sedge

Botanical name: Carex ×oneillii

USDA symbol: CAON

Life cycle: perennial

Habit: grass

Native status: Native to Alaska  

O’Neill’s Sedge: A Rare Alaskan Native for the Adventurous Gardener If you’re the type of gardener who gets excited about rare finds and unusual plants, Carex ×oneillii might just capture your imagination. This native Alaskan sedge is something of a botanical mystery – a hybrid species that’s as elusive as ...

O’Neill’s Sedge: A Rare Alaskan Native for the Adventurous Gardener

If you’re the type of gardener who gets excited about rare finds and unusual plants, Carex ×oneillii might just capture your imagination. This native Alaskan sedge is something of a botanical mystery – a hybrid species that’s as elusive as it is intriguing.

What Makes This Sedge Special?

Carex ×oneillii, commonly known simply as sedge, belongs to the diverse Cyperaceae family. The × in its botanical name tells us something important: this is a hybrid species, which means it arose naturally from the crossing of two different sedge species. This makes it particularly unique and relatively uncommon in the plant world.

As a perennial grass-like plant, this sedge shares characteristics with its sedge cousins – think graceful, arching foliage and a clumping growth habit that adds texture and movement to landscapes.

Where Does It Come From?

This sedge calls Alaska home, where it has adapted to the unique growing conditions of the Last Frontier. Its native range is limited to Alaska, making it a true northern specialty.

Should You Plant O’Neill’s Sedge?

Here’s where things get a bit tricky. While Carex ×oneillii would be a fantastic addition to any native plant collection, finding this particular sedge might prove challenging. As a hybrid species with limited distribution, it’s not commonly available in nurseries or seed catalogs.

If you’re gardening in Alaska or similar northern climates, this sedge could potentially be an excellent choice for:

  • Native plant gardens celebrating local flora
  • Naturalistic landscapes mimicking Alaskan ecosystems
  • Areas where you want authentic regional character
  • Collections focused on rare or unusual sedges

Growing Conditions and Care

While specific growing requirements for Carex ×oneillii aren’t well-documented, we can make educated guesses based on its Alaskan origins and sedge family traits. This plant likely thrives in:

  • Cool, northern climates with short growing seasons
  • Moist to wet soil conditions (typical for many sedges)
  • Partial shade to full sun exposure
  • Well-draining but consistently moist soil

The Reality Check

Let’s be honest – unless you’re specifically collecting rare sedges or live in Alaska with access to local plant sources, you probably won’t find Carex ×oneillii at your local garden center. And that’s okay! The sedge family is wonderfully diverse, with many more readily available species that can give you similar aesthetic benefits.

Alternative Sedges to Consider

If O’Neill’s sedge has piqued your interest in sedges generally, consider these more available options:

  • Pennsylvania sedge (Carex pensylvanica) for eastern gardens
  • California sedge (Carex praegracilis) for western landscapes
  • Buffalo grass sedge (Carex praegracilis) for prairie-style plantings

The Bottom Line

Carex ×oneillii represents the fascinating diversity within the sedge family, but its rarity and limited availability make it more of a botanical curiosity than a practical garden choice for most gardeners. If you do somehow encounter this rare hybrid, consider yourself lucky – you’ve found a true treasure of the northern flora.

For the rest of us, exploring the many other beautiful and available sedge species can provide similar benefits while supporting our local ecosystems with plants that are easier to source and establish.

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 ×oneillii Lepage [lenticularis × rostrata] - sedge

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