North America Native Plant

Peirson’s Aster

Botanical name: Oreostemma peirsonii

USDA symbol: ORPE4

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Aster peirsonii Sharsm. (ASPE2)   

Peirson’s Aster: A Rare California Native Worth Growing Responsibly If you’re passionate about native plants and love supporting conservation efforts right in your own backyard, Peirson’s aster (Oreostemma peirsonii) might just be the perfect addition to your garden. This charming California native brings delicate beauty to landscapes while playing an ...

Rare plant alert!

Region: Conservation status by state

Status: S3: Status is uncertain but is somewhere between the following rankings: 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 ⚘

Peirson’s Aster: A Rare California Native Worth Growing Responsibly

If you’re passionate about native plants and love supporting conservation efforts right in your own backyard, Peirson’s aster (Oreostemma peirsonii) might just be the perfect addition to your garden. This charming California native brings delicate beauty to landscapes while playing an important role in preserving our local biodiversity.

What Makes Peirson’s Aster Special?

Peirson’s aster is a perennial forb that produces lovely daisy-like flowers in shades of white to pale purple. Like other members of the aster family, it blooms in late summer to fall, providing crucial late-season nectar when many other flowers have finished for the year. You might also see this plant listed under its former scientific name, Aster peirsonii.

What truly sets this plant apart, however, is its rarity. Peirson’s aster has a Global Conservation Status of S3, meaning it’s considered vulnerable throughout its range. With only an estimated 21 to 100 occurrences and between 3,000 to 10,000 individuals remaining, this little aster needs our help to survive.

Where Does It Grow?

This California endemic calls the Golden State home exclusively, thriving in desert and montane regions. As a native to the lower 48 states, it’s perfectly adapted to California’s unique climate conditions and plays an important role in local ecosystems.

Why Plant Peirson’s Aster?

There are several compelling reasons to consider adding this rare beauty to your landscape:

  • Conservation impact: By growing Peirson’s aster, you’re directly contributing to the preservation of a vulnerable species
  • Pollinator support: The flowers attract native bees, butterflies, and other beneficial insects, especially during the crucial late-season blooming period
  • Low maintenance: Once established, this drought-tolerant native requires minimal care and water
  • Authentic California gardening: It’s perfectly suited for native plant gardens, xeriscapes, and naturalistic desert landscapes

Growing Conditions and Care

Peirson’s aster is surprisingly easy to grow once you understand its needs. This hardy perennial thrives in USDA zones 8-10 and prefers:

  • Sunlight: Full sun to partial shade
  • Soil: Well-draining soils (essential for preventing root rot)
  • Water: Drought tolerant once established; minimal supplemental watering needed
  • Maintenance: Very low maintenance after the first growing season

Perfect for These Garden Types

Peirson’s aster shines in several landscape settings:

  • Native wildflower gardens
  • Rock gardens and xeriscapes
  • Desert-themed landscapes
  • Conservation-focused plantings
  • Pollinator gardens

Important Note About Sourcing

Here’s the crucial part: if you decide to grow Peirson’s aster, please ensure you source your plants or seeds responsibly. Due to its vulnerable conservation status, it’s essential to purchase from reputable native plant nurseries that propagate their stock rather than wild-collect it. Never collect seeds or plants from wild populations, as this could further threaten already fragile populations.

Contact local native plant societies, botanical gardens, or conservation organizations for recommendations on ethical sources. Some specialty native plant nurseries may be able to special order it for you if they don’t regularly stock it.

The Bottom Line

Peirson’s aster offers gardeners a unique opportunity to grow something truly special while making a positive conservation impact. Its delicate flowers, low-maintenance nature, and important ecological role make it a worthy addition to any California native plant garden. Just remember: responsible sourcing is key to ensuring this rare beauty continues to grace our landscapes for generations to come.

By choosing to grow Peirson’s aster, you’re not just adding a beautiful plant to your garden—you’re becoming a conservation partner in preserving California’s precious native flora.

Peirson’s Aster

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Oreostemma Greene - aster

Species

Oreostemma peirsonii (Sharsm.) G.L. Nesom - Peirson's aster

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