North America Native Plant

Brandegee’s Tansyaster

Botanical name: Machaeranthera coloradoensis var. brandegeei

USDA symbol: MACOB

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Brandegee’s Tansyaster: A Rare Colorado Native Worth Protecting Meet Brandegee’s tansyaster (Machaeranthera coloradoensis var. brandegeei), one of Colorado’s most elusive native wildflowers. This perennial forb might not be a household name in gardening circles, but it represents something truly special in the world of native plants – a genuine Colorado ...

Rare plant alert!

Region: Conservation status by state

Status: S3T2?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Subspecies or variety is 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) ⚘ 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 ⚘

Brandegee’s Tansyaster: A Rare Colorado Native Worth Protecting

Meet Brandegee’s tansyaster (Machaeranthera coloradoensis var. brandegeei), one of Colorado’s most elusive native wildflowers. This perennial forb might not be a household name in gardening circles, but it represents something truly special in the world of native plants – a genuine Colorado endemic that deserves our attention and protection.

What Makes This Plant Special?

Brandegee’s tansyaster belongs to that fascinating group of plants we call forbs – essentially, non-woody flowering plants that add color and diversity to natural landscapes. As a perennial, this hardy little plant returns year after year, though finding it in the wild requires some serious botanical detective work.

What truly sets this plant apart is its incredible rarity. With a Global Conservation Status of S3T2?, Brandegee’s tansyaster is considered quite rare and poorly understood – the question mark in its status indicates that scientists need more information to fully assess its conservation needs.

A True Colorado Native

This tansyaster variety calls Colorado home and nowhere else. It’s what botanists call an endemic species – a plant that evolved in one specific region and can’t be found naturally anywhere else on Earth. For Colorado gardeners, that makes it a true local treasure.

Should You Grow Brandegee’s Tansyaster?

Here’s where things get a bit complicated. While supporting native plants is always admirable, Brandegee’s tansyaster’s rarity status means you need to be extra thoughtful about how you approach growing it.

The responsible approach:

  • Only source plants or seeds from reputable native plant nurseries that can guarantee ethical collection practices
  • Never collect plants or seeds from wild populations
  • Consider this plant only if you’re committed to native plant conservation
  • Connect with local botanical societies or native plant groups for guidance

Growing Conditions and Care

Unfortunately, specific growing information for this rare variety is limited. As a Colorado native forb, it likely adapted to the state’s challenging mountain and high plains conditions – think intense sun, dramatic temperature swings, and well-draining soils.

If you’re lucky enough to source this plant responsibly, treat it like you would other Colorado natives:

  • Provide excellent drainage
  • Expect it to prefer lean soils over rich garden soil
  • Give it plenty of sunshine
  • Be patient – rare natives often establish slowly

Alternative Colorado Natives to Consider

While you’re searching for responsible sources of Brandegee’s tansyaster (or if you decide it’s too rare to risk), consider these other beautiful Colorado natives that are more readily available:

  • Purple Prairie Aster (Symphyotrichum ericoides)
  • Rocky Mountain Aster (Symphyotrichum ericoides var. pansum)
  • Aromatic Aster (Symphyotrichum oblongifolium)

The Bigger Picture

Sometimes the most important thing we can do for a rare plant isn’t growing it in our gardens – it’s protecting the wild places where it still exists. If you’re passionate about Brandegee’s tansyaster, consider supporting Colorado’s natural areas, participating in citizen science projects, or volunteering with organizations that protect native plant habitats.

After all, the best way to ensure future generations can appreciate this rare Colorado gem is to keep its wild populations thriving in their natural homes.

Brandegee’s Tansyaster

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

Machaeranthera Nees - tansyaster

Species

Machaeranthera coloradoensis (A. Gray) Osterh. - Colorado tansyaster

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