North America Native Plant

Rayless Tansyaster

Botanical name: Machaeranthera grindelioides var. grindelioides

USDA symbol: MAGRG

Life cycle: perennial

Habit: subshrub

Native status: Native to Canada âš˜ Native to the lower 48 states  

Synonyms: Eriocarpum grindelioides Nutt. (ERGR14)  âš˜  Haplopappus nuttallii Torr. & A. Gray (HANU2)  âš˜  Sideranthus grindelioides (Nutt.) Britton (SIGR12)   

Rayless Tansyaster: A Hardy Native Wildflower for Water-Wise Gardens If you’re looking for a tough-as-nails native wildflower that laughs in the face of drought and poor soil, meet the rayless tansyaster (Machaeranthera grindelioides var. grindelioides). This unassuming perennial might not have the flashiest name, but it’s a true champion of ...

Rayless Tansyaster: A Hardy Native Wildflower for Water-Wise Gardens

If you’re looking for a tough-as-nails native wildflower that laughs in the face of drought and poor soil, meet the rayless tansyaster (Machaeranthera grindelioides var. grindelioides). This unassuming perennial might not have the flashiest name, but it’s a true champion of low-maintenance gardening and native plant landscaping.

What Is Rayless Tansyaster?

Rayless tansyaster is a native North American perennial forb that belongs to the sunflower family. Despite its common name suggesting otherwise, this plant actually does produce small, cheerful daisy-like flowers. The rayless part of its name comes from the fact that its flower heads sometimes lack the prominent petal-like ray flowers that many of its relatives sport.

This hardy wildflower is also known by several botanical synonyms, including Eriocarpum grindelioides, Haplopappus nuttallii, and Sideranthus grindelioides, so don’t be confused if you see it listed under different names at native plant sales.

Where Does It Grow Naturally?

Rayless tansyaster is native to both Canada and the lower 48 United States, with a wide distribution across the western regions. You’ll find this adaptable plant naturally growing in Alberta, Saskatchewan, Arizona, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, North Dakota, South Dakota, Utah, and Wyoming.

Why Consider Rayless Tansyaster for Your Garden?

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

  • Drought tolerance: Once established, rayless tansyaster thrives with minimal water, making it perfect for xeriscaping and water-wise gardens
  • Native plant benefits: As a true native, it supports local ecosystems and wildlife
  • Pollinator magnet: The small flowers attract native bees, butterflies, and other beneficial insects
  • Low maintenance: This is a plant-it-and-forget-it kind of wildflower that doesn’t demand constant attention
  • Cold hardy: Suitable for USDA hardiness zones 3-8, it can handle some serious winter weather

Perfect Garden Settings

Rayless tansyaster shines in several garden contexts:

  • Rock gardens and gravel gardens
  • Prairie and meadow restorations
  • Native plant gardens
  • Drought-tolerant landscapes
  • Naturalized areas and wildflower meadows
  • Erosion control on slopes

Growing Conditions and Care

This adaptable perennial is refreshingly easy to please:

Sunlight: Prefers full sun for best flowering and compact growth

Soil: Thrives in well-draining soils and actually prefers lean, rocky, or sandy conditions over rich garden soil

Water: Drought tolerant once established; avoid overwatering as it can lead to weak, floppy growth

Fertilizer: None needed – this plant actually prefers poor soils and too much fertility can cause problems

Planting and Establishment Tips

Getting rayless tansyaster established in your garden is straightforward:

  • Plant in spring after the last frost date
  • Space plants 12-18 inches apart
  • Water regularly during the first growing season to help establish roots
  • Once established, reduce watering – this plant prefers to stay on the dry side
  • Consider starting from seed, as rayless tansyaster often self-seeds readily

Wildlife and Pollinator Benefits

While rayless tansyaster might look modest, it punches above its weight when it comes to supporting wildlife. The flowers provide nectar for various native bees, butterflies, and other small pollinators. Birds may also feed on the seeds later in the season.

Potential Drawbacks to Consider

Like any plant, rayless tansyaster isn’t perfect for every situation:

  • It’s not the showiest wildflower – if you want dramatic blooms, look elsewhere
  • Can self-seed prolifically in ideal conditions, which some gardeners might find weedy
  • May go dormant during extreme heat or drought, temporarily disappearing above ground

The Bottom Line

Rayless tansyaster is an excellent choice for gardeners who want to support native ecosystems while creating a low-maintenance, drought-tolerant landscape. It’s particularly valuable in regions within its native range, where it can provide authentic habitat for local wildlife while requiring minimal care once established. While it may not be the star of your flower border, it’s exactly the kind of reliable, hardworking native plant that forms the backbone of successful wildflower gardens and prairie restorations.

Rayless 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 grindelioides (Nutt.) Shinners - rayless tansyaster

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