North America Native Plant

Idaho Goldenweed

Botanical name: Tonestus aberrans

USDA symbol: TOAB

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Haplopappus aberrans (A. Nelson) H.M. Hall (HAAB)  âš˜  Macronema aberrans A. Nelson (MAAB3)   

Idaho Goldenweed: A Rare Native Treasure Worth Protecting If you’re a native plant enthusiast with a passion for rare species, you might have stumbled across Idaho goldenweed in your research. This little-known perennial herb has a story that’s both fascinating and concerning – one that every responsible gardener should understand ...

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 ⚘

Idaho Goldenweed: A Rare Native Treasure Worth Protecting

If you’re a native plant enthusiast with a passion for rare species, you might have stumbled across Idaho goldenweed in your research. This little-known perennial herb has a story that’s both fascinating and concerning – one that every responsible gardener should understand before considering it for their landscape.

Meet Idaho Goldenweed

Idaho goldenweed (Tonestus aberrans) is a perennial forb herb that belongs to the sunflower family. You might also find it listed under its former scientific names, Haplopappus aberrans or Macronema aberrans, in older botanical references. As a forb, it’s essentially a non-woody flowering plant that dies back to its roots each winter and returns the following spring.

Where Does It Call Home?

This native beauty has one of the most restricted ranges you’ll find among North American wildflowers. Idaho goldenweed grows naturally only in Idaho and Montana, making it a true regional endemic. Its limited distribution is part of what makes this plant so special – and so vulnerable.

A Plant in Need of Protection

Here’s where things get serious: Idaho goldenweed has a Global Conservation Status of S3, meaning it’s considered vulnerable. With only 21 to 100 known occurrences and an estimated 3,000 to 10,000 individual plants in the wild, this species walks a tightrope between survival and extinction.

What does this mean for gardeners? If you’re considering growing Idaho goldenweed, you absolutely must ensure any plants or seeds come from responsible, ethical sources that don’t impact wild populations. Never collect from the wild, and be extremely cautious about commercial sources.

Garden Appeal and Growing Conditions

Idaho goldenweed produces small, cheerful yellow flowers typical of its sunflower family heritage. As a low-growing perennial, it would likely work well in rock gardens or specialized native plant collections. However, specific information about its exact growing requirements, size, and care needs is limited due to its rarity and restricted cultivation.

Based on its native range in Idaho and Montana, Idaho goldenweed likely prefers:

  • Well-drained soils
  • Full sun to partial shade
  • Cool to moderate temperatures (probably hardy in USDA zones 4-6)
  • Low to moderate water requirements

Wildlife and Pollinator Value

While specific research on Idaho goldenweed’s wildlife benefits is limited, plants in the sunflower family typically provide valuable nectar sources for native bees, butterflies, and other pollinators. Given its rarity, it may have specialized relationships with particular insects in its native ecosystem.

Should You Grow Idaho Goldenweed?

This is a complex question that requires careful consideration. While supporting rare native plants through cultivation can be valuable for conservation, Idaho goldenweed’s vulnerable status means extreme caution is warranted.

Consider these alternatives instead:

  • Other native goldenweed species with more stable populations
  • Common native plants that support similar pollinators
  • Regionally appropriate native wildflowers from the sunflower family

If you absolutely must grow Idaho goldenweed, work only with reputable native plant societies, botanical gardens, or conservation organizations that can verify ethical sourcing and may be involved in legitimate conservation efforts.

The Bottom Line

Idaho goldenweed represents both the beauty and fragility of our native plant heritage. While it’s tempting to want to grow every rare and wonderful species we encounter, sometimes the most loving thing we can do is admire from a distance and focus our garden efforts on more common natives that won’t put additional pressure on vulnerable wild populations.

Instead of growing Idaho goldenweed, consider supporting its conservation by donating to organizations working to protect its native habitat or volunteering for native plant monitoring programs in the Mountain West. That way, future generations might still have the chance to encounter this golden treasure in its natural home.

Idaho Goldenweed

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

Tonestus A. Nelson - serpentweed

Species

Tonestus aberrans (A. Nelson) G.L. Nesom & D. Morgan - Idaho goldenweed

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