North America Native Plant

Colorado Tansyaster

Botanical name: Machaeranthera coloradoensis var. coloradoensis

USDA symbol: MACOC

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Aster coloradoensis A. Gray (ASCO28)  âš˜  Eriocarpum coloradoense (A. Gray) Greene (ERCO30)  âš˜  Haplopappus coloradoensis (A. Gray) R.L. Hartm. ex Dorn (HACO5)  âš˜  Xanthisma coloradoense (A. Gray) D.R. Morgan & R.L. Hartm. (XACO8)  âš˜  Xylorhiza coloradoensis (A. Gray) Rydb. (XYCO4)   

Colorado Tansyaster: A Rare High-Altitude Beauty for Your Native Garden If you’re looking to add a touch of Rocky Mountain magic to your garden, the Colorado tansyaster might just be your perfect match. This charming native wildflower brings the rugged beauty of high-altitude meadows right to your backyard, complete with ...

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 ⚘

Colorado Tansyaster: A Rare High-Altitude Beauty for Your Native Garden

If you’re looking to add a touch of Rocky Mountain magic to your garden, the Colorado tansyaster might just be your perfect match. This charming native wildflower brings the rugged beauty of high-altitude meadows right to your backyard, complete with cheerful purple blooms that butterflies absolutely adore.

Meet the Colorado Tansyaster

Scientifically known as Machaeranthera coloradoensis var. coloradoensis, this perennial forb is a true Rocky Mountain native. Like many plants with complex botanical names, it has gone through quite a few name changes over the years—botanists have also called it Aster coloradoensis, Xanthisma coloradoense, and several other tongue-twisting titles. But don’t let the scientific shuffling fool you; this is one special little plant that deserves a spot in the right garden.

Where Does It Call Home?

The Colorado tansyaster is wonderfully picky about its neighborhood—it’s found exclusively in Colorado and Wyoming, making it a true regional treasure. This limited range means you’re growing something genuinely unique that most gardeners will never encounter.

A Word About Rarity

Here’s something important to know: Colorado tansyaster has a conservation status that suggests it may be uncommon in the wild. While this shouldn’t discourage you from growing it, it does mean you should be extra thoughtful about where you source your plants. Always choose nurseries that grow their stock from seed rather than wild-collecting, and never dig plants from natural areas. By growing responsibly sourced Colorado tansyaster, you’re actually helping preserve this beautiful species!

Why Your Garden Will Love This Plant

Colorado tansyaster is the kind of plant that makes you look like a gardening genius without much effort. As a non-woody perennial herb, it comes back year after year, producing clusters of purple to violet daisy-like flowers with bright yellow centers. The blooms typically appear in late summer through fall, providing crucial late-season nectar when many other flowers have called it quits.

This tough little beauty is perfect for:

  • Rock gardens and alpine-style landscapes
  • Drought-tolerant xerophytic gardens
  • Native plant collections
  • Naturalized meadow areas
  • Wildlife and pollinator gardens

Growing Colorado Tansyaster Successfully

The good news is that Colorado tansyaster is surprisingly low-maintenance once you understand its needs. Think of it as a plant that prefers the less is more approach to garden care.

Sunlight: This sun-lover thrives in full sun conditions, so give it the brightest spot in your garden.

Soil: Well-draining soil is absolutely crucial. Colorado tansyaster comes from high-altitude areas where water doesn’t stick around long, so soggy conditions will quickly spell trouble.

Water: Once established, this plant is remarkably drought-tolerant. Water it regularly during its first growing season, then step back and let nature take over.

Climate: Hardy in USDA zones 4-7, Colorado tansyaster can handle cold winters but appreciates some winter mulch in the coldest areas.

Planting and Care Tips

Plant Colorado tansyaster in spring after the last frost. Space plants appropriately based on their mature size, and don’t worry too much about fertilizing—these mountain natives prefer lean conditions. The most important care tip? Don’t overwater! More Colorado tansyasters meet their demise from kindness (too much water) than neglect.

Supporting Wildlife

One of the best reasons to grow Colorado tansyaster is its value to local wildlife. The late-season flowers provide crucial nectar for butterflies, native bees, and other pollinators when food sources are becoming scarce. It’s like setting up a autumn buffet for your local pollinator community.

Is Colorado Tansyaster Right for Your Garden?

This plant is perfect if you love native species, want to support local wildlife, and prefer low-maintenance gardening. It’s especially ideal for gardeners dealing with dry conditions or those creating specialized rock and alpine gardens. However, if you’re looking for a plant with a long blooming season or prefer lush, tropical-looking gardens, you might want to consider other options.

Remember, by choosing to grow Colorado tansyaster from responsibly sourced plants, you’re not just adding beauty to your garden—you’re helping preserve a special piece of Rocky Mountain heritage. And really, how cool is it to tell visitors that you’re growing something that exists nowhere else in the world except Colorado and Wyoming?

Colorado 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