North America Native Plant

Atwood’s Buckwheat

Botanical name: Eriogonum thompsoniae var. atwoodii

USDA symbol: ERTHA2

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Eriogonum corymbosum Benth. var. atwoodii (Reveal) S.L. Welsh (ERCOA6)   

Atwood’s Buckwheat: A Rare Arizona Native Worth Protecting If you’re looking to add a truly special native plant to your Arizona garden, let me introduce you to Atwood’s buckwheat (Eriogonum thompsoniae var. atwoodii). This little-known perennial is one of those hidden gems that deserves more attention – though for very ...

Rare plant alert!

Region: Conservation status by state

Status: S4T1: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Atwood’s Buckwheat: A Rare Arizona Native Worth Protecting

If you’re looking to add a truly special native plant to your Arizona garden, let me introduce you to Atwood’s buckwheat (Eriogonum thompsoniae var. atwoodii). This little-known perennial is one of those hidden gems that deserves more attention – though for very important conservation reasons, we need to be thoughtful about how we go about growing it.

What Makes Atwood’s Buckwheat Special?

Atwood’s buckwheat is a charming perennial forb that belongs to the vast Eriogonum family – Arizona’s beloved buckwheats. Unlike its more common cousins, this particular variety is found only in Arizona, making it a true local treasure. As a herbaceous perennial, it lacks the woody stems of shrubs and trees, instead producing delicate flowering stems that emerge from a ground-hugging base each growing season.

You might also see this plant listed under its synonym, Eriogonum corymbosum var. atwoodii, in older references, but rest assured – we’re talking about the same special plant.

Where Does It Call Home?

This buckwheat is exclusively native to Arizona, where it has adapted to the unique conditions of the Colorado Plateau region. Its limited geographic distribution is part of what makes it so special – and so vulnerable.

A Word About Rarity

Here’s where things get serious, fellow gardeners. Atwood’s buckwheat carries a Global Conservation Status of S4T1, which indicates it’s quite rare in the wild. This means that if you’re considering adding this beauty to your garden, you absolutely must source it responsibly. Never collect plants or seeds from wild populations – this could seriously harm the species’ survival. Instead, work with reputable native plant nurseries that propagate their stock ethically.

Garden Appeal and Design Ideas

When responsibly sourced, Atwood’s buckwheat can be a wonderful addition to the right garden setting. Like most buckwheats, it likely produces clusters of small, attractive flowers that range from white to soft pink – a magnet for native pollinators including bees and butterflies. Its low, herbaceous growth habit makes it perfect for:

  • Rock gardens and xeriscapes
  • Native plant gardens focused on Arizona species
  • Drought-tolerant landscape designs
  • Pollinator-friendly garden spaces

Growing Conditions and Care

As an Arizona native adapted to challenging conditions, Atwood’s buckwheat likely prefers:

  • Sun exposure: Full sun to light shade
  • Soil: Well-draining, rocky or sandy soils
  • Water: Minimal once established – drought tolerance is key
  • Climate: Suitable for USDA hardiness zones 5-9

The cardinal rule with most buckwheats is to avoid overwatering. These plants have evolved to thrive with minimal moisture, and too much water can lead to root rot and other problems.

Supporting Pollinators and Wildlife

While specific data on wildlife benefits isn’t widely documented for this rare variety, buckwheat family plants are generally excellent pollinator magnets. The flowers provide nectar and pollen for native bees, beneficial wasps, and butterflies. Some buckwheats also produce seeds that feed birds and small mammals.

Planting and Care Tips

If you’re fortunate enough to find responsibly sourced Atwood’s buckwheat:

  • Plant in well-draining soil – add gravel or sand if needed
  • Choose a sunny location
  • Water sparingly during establishment, then reduce to minimal supplemental irrigation
  • Avoid fertilizers – these plants prefer lean soils
  • Allow flowers to go to seed to support wildlife

The Bottom Line

Atwood’s buckwheat represents both an opportunity and a responsibility. As gardeners, we have the chance to help conserve this rare Arizona native by growing it thoughtfully in our landscapes. However, we must always prioritize the wild populations by sourcing plants only from ethical suppliers who propagate rather than wild-collect their stock.

If you can’t find responsibly sourced Atwood’s buckwheat, consider other Arizona native buckwheats that are more readily available and equally beautiful. Every native plant we grow is a step toward supporting our local ecosystems – and sometimes the most loving thing we can do for a rare plant is to admire it in the wild while growing its more common relatives at home.

Atwood’s Buckwheat

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Caryophyllidae

Order

Polygonales

Family

Polygonaceae Juss. - Buckwheat family

Genus

Eriogonum Michx. - buckwheat

Species

Eriogonum thompsoniae S. Watson - Thompson's buckwheat

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