North America Native Plant

Hoary Tansyaster

Botanical name: Machaeranthera canescens canescens var. ambigua

USDA symbol: MACAA

Life cycle: biennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Machaeranthera angustifolia Wooton & Standl. (MAAN10)  âš˜  Machaeranthera oxylepis Greene (MAOX)  âš˜  Machaeranthera scoparia Greene (MASC2)   

Hoary Tansyaster: A Hidden Gem for Southwest Native Gardens If you’re looking to add some authentic southwestern charm to your garden, let me introduce you to the hoary tansyaster (Machaeranthera canescens canescens var. ambigua). This delightful native wildflower might not roll off the tongue easily, but it’s definitely worth getting ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3T4: 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. ⚘ Subspecies or varieties is apparently secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the region 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. ⚘

Hoary Tansyaster: A Hidden Gem for Southwest Native Gardens

If you’re looking to add some authentic southwestern charm to your garden, let me introduce you to the hoary tansyaster (Machaeranthera canescens canescens var. ambigua). This delightful native wildflower might not roll off the tongue easily, but it’s definitely worth getting to know!

What Exactly Is Hoary Tansyaster?

Hoary tansyaster is a native forb – that’s gardener-speak for a non-woody flowering plant. Think of it as nature’s way of adding splashes of color to the landscape without all the fuss of shrubs or trees. This versatile little plant can live its life as an annual, biennial, or perennial, making it quite the shape-shifter in the plant world.

You might also encounter this plant under some of its former names, including Machaeranthera angustifolia, Machaeranthera oxylepis, or Machaeranthera scoparia. Plant names can be as changeable as fashion trends sometimes!

Where Does It Call Home?

This southwestern beauty is native to three states: Arizona, Colorado, and New Mexico. It’s perfectly adapted to the unique conditions of the American Southwest, making it an excellent choice for gardeners in these regions who want to work with nature rather than against it.

Why Consider Hoary Tansyaster for Your Garden?

There are several compelling reasons to give this native plant a spot in your landscape:

  • Authentically native: You’ll be supporting local ecosystems and wildlife
  • Adapted to local conditions: Once established, it should thrive with minimal intervention
  • Flexible lifecycle: Whether it grows as an annual or perennial in your garden, it’ll adapt to your local conditions
  • Low-maintenance: Native plants typically require less water, fertilizer, and pest control

A Word About Conservation

Here’s something important to keep in mind: hoary tansyaster has a conservation status that suggests it may be somewhat uncommon in parts of its range. If you decide to grow this plant, please make sure you source it responsibly. Look for reputable native plant nurseries or seed suppliers who ethically collect and propagate their stock. Never collect seeds or plants from wild populations without proper permits and knowledge.

Growing Hoary Tansyaster Successfully

While specific growing information for this particular variety is limited, we can make some educated guesses based on its native habitat and plant family characteristics. As a southwestern native, it likely prefers:

  • Well-draining soils (soggy feet are probably not its thing)
  • Full sun to partial shade
  • Moderate to low water once established
  • Rocky or sandy soil conditions typical of its native range

What We’d Love to Know More About

Honestly, there’s still quite a bit of mystery surrounding the specific cultivation requirements for hoary tansyaster. This presents both a challenge and an opportunity for adventurous gardeners! If you decide to grow this plant, you’ll be contributing to our collective knowledge about native plant cultivation.

Some questions we’d love answers to include: What are its preferred soil conditions? How does it respond to different watering regimes? What kind of wildlife does it attract? How tall and wide does it typically grow?

The Bottom Line

Hoary tansyaster represents the kind of authentic, regionally appropriate plant that can make southwestern gardens truly special. While we may not have all the cultivation details figured out yet, its native status and natural adaptation to the region make it worth considering for gardeners who want to create landscapes that celebrate local flora.

Just remember: if you choose to grow this plant, source it responsibly and consider yourself a pioneer in native plant gardening. Who knows? Your experience might help other gardeners successfully cultivate this southwestern gem!

Have you grown hoary tansyaster in your garden? We’d love to hear about your experiences with this intriguing native plant.

Hoary 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 canescens (Pursh) A. Gray - hoary tansyaster

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