North America Native Plant

Largeglume Bluegrass

Botanical name: Poa macrocalyx

USDA symbol: POMA2

Life cycle: perennial

Habit: grass

Native status: Native to Alaska âš˜ Native to Canada  

Synonyms: Poa hispidula Vasey (POHI)  âš˜  Poa hispidula Vasey var. aleutica Hultén (POHIA)  âš˜  Poa hispidula Vasey var. vivipara Hultén (POHIV)  âš˜  Poa norbergii Hultén (PONO)  âš˜  Poa turneri Scribn. (POTU)   

Largeglume Bluegrass: A Rare Arctic Native Worth Knowing If you’re fascinated by rare native grasses and have a garden in the far north, largeglume bluegrass (Poa macrocalyx) might just pique your interest. This perennial grass is one of nature’s hardy survivors, adapted to some of North America’s most challenging climates. ...

Rare plant alert!

Region: Conservation status by state

Status: S1?Q: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Uncertain taxonomy: ⚘ 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) ⚘ 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 ⚘

Region: Conservation status by state

Largeglume Bluegrass: A Rare Arctic Native Worth Knowing

If you’re fascinated by rare native grasses and have a garden in the far north, largeglume bluegrass (Poa macrocalyx) might just pique your interest. This perennial grass is one of nature’s hardy survivors, adapted to some of North America’s most challenging climates.

What is Largeglume Bluegrass?

Largeglume bluegrass is a perennial grass native to the arctic and subarctic regions of Alaska and British Columbia. As a member of the graminoid family, it shares characteristics with other grasses, sedges, and rushes – those fine-textured, often overlooked plants that actually form the backbone of many ecosystems.

This species goes by several scientific synonyms, including Poa hispidula, Poa norbergii, and Poa turneri, which might explain why information about it can be scattered across different sources.

Where Does It Grow Naturally?

You’ll find largeglume bluegrass in its native range across Alaska and British Columbia, where it has adapted to harsh northern conditions that would challenge most other plants.

Should You Plant Largeglume Bluegrass?

Here’s where things get a bit complicated. Largeglume bluegrass has a conservation status that suggests it may be rare or uncommon in parts of its range. If you’re interested in growing this species, it’s crucial to source it responsibly from reputable native plant suppliers who can verify the plant material wasn’t collected from wild populations.

Growing Conditions and Care

Given its arctic origins, largeglume bluegrass likely thrives in:

  • Cool climates (probably USDA zones 1-4)
  • Moist to moderately wet soils (it has a facultative wetland status, meaning it can handle both wet and drier conditions)
  • Full sun to partial shade
  • Well-draining soils that don’t stay waterlogged

Unfortunately, detailed cultivation information for this species is quite limited, which isn’t surprising given its specialized native range and rarity.

Garden Uses and Landscape Role

If you live in the far north and can source this grass responsibly, largeglume bluegrass could serve as:

  • A naturalized ground cover in arctic or alpine garden settings
  • Part of a native grass restoration project
  • An interesting addition to collections of rare native plants

Wildlife and Ecological Benefits

Like most native grasses, largeglume bluegrass likely provides some ecological benefits, though specific wildlife relationships aren’t well-documented. As a wind-pollinated grass, it won’t attract pollinators like flowering plants do, but it may provide habitat and food for small mammals and birds in its native range.

The Bottom Line

Largeglume bluegrass is definitely a plant for specialized situations and dedicated native plant enthusiasts. Its rarity means it’s not something to plant casually, and its arctic origins limit where it can successfully grow. If you’re in Alaska or northern British Columbia and passionate about preserving native plant diversity, this could be a worthwhile addition – but only with responsibly sourced material.

For most gardeners, especially those in warmer climates, there are many other native grass species that would be more appropriate and easier to establish. Consider exploring native grasses that are better suited to your local conditions and more readily available from ethical sources.

Largeglume Bluegrass

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

Poa L. - bluegrass

Species

Poa macrocalyx Trautv. & C.A. Mey. - largeglume bluegrass

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