

Davidson's Buckwheat Eriogonum davidsonii
Davidson's Buckwheat is an annual wildflower native to the lower 48 states. It blooms Apr – Oct. A host for pollen-specialist native bees.
More about this plant
Eriogonum davidsonii is a species of wild buckwheat known by the common name Davidson's buckwheat. This plant is native to the southwestern United States and northern Baja California. It grows in sandy or gravelly soils, mixed grassland, saltbush, chaparral, sagebrush communities as well as oak and montane conifer woodland. It is a spindly annual herb growing up to 40 centimeters in height. Leaves are fuzzy, basal, and round with wavy or wrinkly margins fuzzy. They are two centimeters wide. The plant is variable in appearance, but is usually erect with thin, naked, neatly branching stems bearing clusters of tiny flowers at widely spaced nodes. Each flower is about 2 millimeters wide, bell-shaped, and can be white, pink or red. Flowering occurs May to September. Wikipedia →
Growing & care
USDA PLANTS · TRY- Hardiness
- ≥ zone 8 derived from its U.S. range
- Lifespan
- Annual
- Foliage
- Broadleaf
- Flower colour
- Pink AI AI image-analysis of community-science photos (~87% expert agreement) — not a botanical record
Wildlife & pollinators
How pollinator value is scored →❧ Caterpillar hosts ~9 caterpillar species
Eriogonum supports ~9 caterpillar species.
Native butterfly & moth caterpillars are the base of the terrestrial food web — most songbirds rear their young almost entirely on them. As a host for native Lepidoptera this is a modest genus.
Recorded feeding on Eriogonum in North America, including:
+ 8 more species → ↑ show fewer
✦ Bees specialist-bee host
Specialist native bees depend on it.
Some native bees are pollen specialists (oligolectic) — they raise young only on pollen from particular plant genera. Eriogonum is a recorded specialist-bee host, so losing it can mean losing the bee that relies on it.
How we know this (2) Methods & honest limits
We take the plant’s U.S. county range and look up each county’s long-term climate, then summarise: native rainfall = the median annual rainfall across its counties; heat tolerance = the warm end (90th percentile) of average temperature across its range (mirroring how our cold-hardiness floor uses an extreme). Counties + medians blunt the roadside/observer bias that makes point-level climate unreliable. Needs at least five placeable counties.
Honest limits: A realized, sampling-biased niche (where it has been recorded, not its physiological optimum), and county climate is coarse — large Western counties span deserts and mountains. Derived guide, never a measured fact.
McKenzie et al. assigned each species a flower colour with a GPT-4V vision model over iNaturalist photos. We use the confident tier plus a separately-labelled lower-confidence top-up (mostly inconspicuous green/brown flowers), and render it as a small tint — never as an asserted fact, and kept out of the written synopsis.
Honest limits: AI image inference (~87% expert agreement on the confident tier); a decorative, confidence-tiered indicator, not a measured trait.
Sources for this entry (18) Open & cited
Cite this page Open data, please attribute
PlantKey’s data is open under CC BY-SA 4.0 — free to reuse and adapt, with attribution and the same licence. Photos keep their own per-image licence + credit (see Sources above).
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