Native Plants

Bolander’s Onion

Allium bolanderi var. stenanthum

USDA symbol: ALBOS

perennial forb

Lower 48 states: native

If you’re a native plant enthusiast with a passion for California’s unique flora, you might have come across the name Bolander’s onion (Allium bolanderi var. stenanthum). This intriguing little perennial belongs to the onion family and represents one of California’s more elusive native treasures. Bolander’s onion is a perennial forb, ...

Bolander’s Onion may be listed as rare in your area.
Global Conservation Status

Status: S4T1T2Q | Apparently Secure: Uncommon but not rare, and usually widespread. Possible cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals.

Bolander’s Onion: A Rare California Native Worth Protecting

If you’re a native plant enthusiast with a passion for California’s unique flora, you might have come across the name Bolander’s onion (Allium bolanderi var. stenanthum). This intriguing little perennial belongs to the onion family and represents one of California’s more elusive native treasures.

What Makes This Plant Special?

Bolander’s onion is a perennial forb, meaning it’s a non-woody plant that returns year after year. Like other members of the Allium family, it likely produces small, delicate flowers that would add a subtle charm to any garden setting. However, what makes this plant truly special isn’t just its botanical characteristics—it’s its incredible rarity.

A California Endemic with Conservation Concerns

This native onion is found exclusively in California, making it a true Golden State endemic. Its scientific name honors Henry Nicholas Bolander, a 19th-century botanist who made significant contributions to California’s botanical knowledge.

  • Species observed
  • No observations

However, here’s where things get serious: Allium bolanderi var. stenanthum carries a Global Conservation Status of S4T1T2Q, indicating it’s extremely rare and potentially at risk. This isn’t a plant you’ll stumble upon during a casual hike, and it’s certainly not something you should consider digging up from the wild.

Should You Grow Bolander’s Onion?

While the idea of growing such a rare California native might be tempting, there are important considerations:

  • Rarity concerns: This plant’s extremely limited distribution means wild populations are vulnerable
  • Sourcing challenges: Finding responsibly propagated material is extremely difficult
  • Growing requirements: Specific habitat needs are not well-documented for home cultivation
  • Conservation priority: Protecting existing wild populations should be the primary focus

Better Alternatives for Your Garden

Instead of seeking out this rare variety, consider other California native Allium species that are more readily available and better suited for home gardens:

  • Allium haematochiton (Red-skinned onion)
  • Allium unifolium (One-leaf onion)
  • Allium drummondii (Drummond’s onion)

These alternatives can provide similar aesthetic appeal while supporting local ecosystems without putting pressure on rare plant populations.

How You Can Help

If you’re passionate about California’s rare plants like Bolander’s onion, consider:

  • Supporting botanical gardens and conservation organizations working to protect rare species
  • Participating in citizen science projects that monitor rare plant populations
  • Choosing more common native alternatives for your garden
  • Learning to identify and report rare plant sightings to local botanists

While we may not be able to grow Bolander’s onion in our gardens, we can certainly appreciate its role in California’s incredible botanical diversity and work to ensure it continues to thrive in its natural habitat for future generations to discover and study.

Allium bolanderi var. stenanthum is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Allium bolanderi var. stenanthum is also known as:

Allium stenanthum | USDA symbol: ALST5

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Monocot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Liliopsida - Monocotyledons
Subclass: Liliidae
Order: Liliales
Family: Liliaceae Juss. - Lily family
Genus: Allium L. - onion

Species: Allium bolanderi S. Watson - Bolander's onion

Variety: Allium bolanderi S. Watson var. stenanthum (E. Drew) Jeps. - Bolander's onion

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