North America Native Plant

Sevendevils Onion

Botanical name: Allium tolmiei var. persimile

USDA symbol: ALTOP

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Sevendevils Onion: A Rare Idaho Native Worth Growing Meet the sevendevils onion (Allium tolmiei var. persimile), a charming little wildflower that’s as unique as its name suggests. This delicate native perennial might not be the flashiest plant in your garden, but it brings something special to the table – authentic ...

Rare plant alert!

Region: Conservation status by state

Status: S4S5T3: Status is uncertain but is somewhere between the following rankings: 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. ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Sevendevils Onion: A Rare Idaho Native Worth Growing

Meet the sevendevils onion (Allium tolmiei var. persimile), a charming little wildflower that’s as unique as its name suggests. This delicate native perennial might not be the flashiest plant in your garden, but it brings something special to the table – authentic Idaho heritage and a story of botanical rarity that makes it worth seeking out.

What Makes Sevendevils Onion Special

This petite member of the onion family is a true Idaho original, found naturally only in the rugged Seven Devils Mountains region. As a perennial forb, it returns year after year with minimal fuss, producing clusters of small purple-pink flowers that dance above slender, grass-like foliage. The blooms appear in neat little umbels – think tiny fireworks frozen in time – that add a subtle but distinctive touch to any native plant collection.

Where It Calls Home

Sevendevils onion is exclusively native to Idaho, making it a true regional treasure. This narrow geographic distribution is part of what makes this plant so special, but it’s also why gardeners need to be thoughtful about how they source it.

A Word About Rarity

Important: This plant has a Global Conservation Status of S4S5T3, indicating it has limited distribution and populations. If you’re interested in growing sevendevils onion, please ensure you purchase from reputable native plant nurseries that propagate their stock responsibly rather than collecting from wild populations. Never dig plants from their natural habitat.

Why Grow Sevendevils Onion?

Here’s why this unassuming little native deserves a spot in your garden:

  • Pollinator magnet: The flowers attract native bees, butterflies, and other beneficial insects
  • Low maintenance: Once established, it requires minimal care and watering
  • Authentic native appeal: Perfect for gardeners wanting to showcase true regional flora
  • Rock garden star: Ideal size and growing habits for alpine and rock garden settings
  • Conversation starter: The unique name and rare status make it a garden talking point

Perfect Garden Settings

Sevendevils onion shines in specialized garden environments where its modest size and specific needs are appreciated:

  • Rock gardens and alpine settings
  • Native plant demonstration gardens
  • Naturalized wildflower areas
  • Collections focused on rare or regionally significant plants

Growing Conditions and Care

This mountain native appreciates conditions that mimic its natural highland habitat:

  • Sunlight: Full sun to partial shade
  • Soil: Well-draining soil is essential – avoid heavy clay or waterlogged conditions
  • Hardiness: Suitable for USDA zones 4-7
  • Water: Drought tolerant once established, but benefits from occasional watering during active growth
  • Dormancy: Goes dormant in summer heat, which is completely normal

Planting and Care Tips

Success with sevendevils onion comes from understanding its mountain origins:

  • Plant bulbs in fall for spring emergence
  • Choose a location with excellent drainage – consider raised beds or slopes
  • Allow the foliage to die back naturally to feed the bulb
  • Mulch lightly to retain moisture during active growth periods
  • Be patient – it may take a season or two to fully establish

The Bottom Line

Sevendevils onion isn’t for every garden or every gardener. Its specialized needs and modest appearance make it best suited for dedicated native plant enthusiasts and those creating authentic regional landscapes. However, if you’re passionate about preserving Idaho’s botanical heritage and have the right growing conditions, this rare little onion can be a meaningful addition to your garden.

Just remember – with rarity comes responsibility. Choose your sources carefully, and help ensure that future generations can appreciate this unique piece of Idaho’s natural heritage, both in the wild and in thoughtfully cultivated gardens.

Sevendevils Onion

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Liliidae

Order

Liliales

Family

Liliaceae Juss. - Lily family

Genus

Allium L. - onion

Species

Allium tolmiei (Hook.) Baker ex S. Watson - Tolmie'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