North America Native Plant

Smallhead Heathgoldenrod

Botanical name: Tonestus microcephalus

USDA symbol: TOMI

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Haplopappus microcephalus Cronquist (HAMI2)   

Smallhead Heathgoldenrod: A Rare Mountain Gem Worth Protecting Meet smallhead heathgoldenrod (Tonestus microcephalus), a delightful little wildflower that’s become something of a botanical treasure in the American West. This charming native perennial might not be the showiest plant in your garden, but it carries the kind of story that makes ...

Rare plant alert!

Region: Conservation status by state

Status: S2: Status is uncertain but is somewhere between the following rankings: Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Smallhead Heathgoldenrod: A Rare Mountain Gem Worth Protecting

Meet smallhead heathgoldenrod (Tonestus microcephalus), a delightful little wildflower that’s become something of a botanical treasure in the American West. This charming native perennial might not be the showiest plant in your garden, but it carries the kind of story that makes plant enthusiasts’ hearts skip a beat.

What Makes This Plant Special

Smallhead heathgoldenrod is a perennial forb herb, meaning it’s a non-woody plant that comes back year after year with its growing points tucked safely at or below ground level. Think of it as nature’s way of playing it safe in harsh mountain environments. The plant produces small yellow composite flowers typical of the sunflower family, creating a subtle but cheerful display during its blooming season.

Where Does It Call Home?

This native beauty has a rather exclusive address – you’ll only find it naturally growing in the high-elevation areas of Colorado and New Mexico. It’s perfectly adapted to the challenging conditions of mountain life, where dramatic temperature swings and intense UV radiation would leave many other plants wilting.

The Conservation Reality Check

Here’s where things get serious: Smallhead heathgoldenrod has a Global Conservation Status of S2, which means it’s considered Imperiled. In plain English, this little plant is extremely rare, with typically only 6 to 20 known occurrences and possibly just 1,000 to 3,000 individual plants remaining in the wild.

What does this mean for gardeners? While we absolutely encourage supporting native plants, this particular species requires extra consideration. If you’re determined to grow smallhead heathgoldenrod, you must source it responsibly from reputable native plant nurseries that propagate rather than wild-collect their stock.

Garden Role and Design Ideas

In the right setting, smallhead heathgoldenrod can be a fascinating addition to:

  • Native wildflower gardens focused on high-elevation species
  • Rock gardens that mimic alpine conditions
  • Conservation gardens dedicated to rare native plants
  • Educational landscapes highlighting regional biodiversity

Growing Conditions and Care

Based on its native habitat, smallhead heathgoldenrod likely thrives in:

  • Sunlight: Full sun exposure
  • Soil: Well-draining, possibly rocky or sandy soils that mimic mountain conditions
  • Water: Drought-tolerant once established, adapted to natural precipitation patterns
  • Hardiness: Likely suitable for USDA zones 4-7, based on its native range

Pollinator and Wildlife Benefits

As a member of the Asteraceae family, smallhead heathgoldenrod likely provides nectar and pollen for native bees, small butterflies, and other pollinators that have co-evolved with mountain wildflowers. Supporting rare native plants like this one helps maintain the intricate web of relationships that keep ecosystems healthy.

The Bottom Line for Gardeners

Should you plant smallhead heathgoldenrod? The answer is a qualified maybe. If you:

  • Have the specific growing conditions it needs
  • Can source it from a reputable nursery that propagates rather than wild-collects
  • Are committed to conservation and education
  • Live within or near its native range

Then yes, growing this rare beauty could be a meaningful way to participate in plant conservation. However, if you’re looking for easier native alternatives that provide similar benefits without conservation concerns, consider other regional Asteraceae family members that are more common and readily available.

Remember, sometimes the best way to support a rare plant is to protect its existing habitat rather than trying to grow it in our gardens. But for those special situations where cultivation makes sense, smallhead heathgoldenrod offers a unique opportunity to connect with one of nature’s more exclusive club members.

Smallhead Heathgoldenrod

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 microcephalus (Cronquist) G.L. Nesom & D. Morgan - smallhead heathgoldenrod

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