

White Wood Aster Eurybia divaricata
White Wood Aster is a perennial wildflower native to Canada and the lower 48 states. It blooms Aug – Oct. A host for pollen-specialist native bees.
More about this plant
Eurybia divaricata, the white wood aster, is an herbaceous plant native to eastern North America. It occurs in the eastern United States, primarily in the Appalachian Mountains, though it is also present in southeastern Canada, in the provinces of Ontario, Quebec and Nova Scotia. In the U.S. it is abundant and common, but in Canada it is considered threatened due to its restricted distribution. It has been introduced to a number of countries in Europe. It can be found in dry open woods as well as along wood-edges and clearings. The species is distinguished by its flower heads that have yellow centers and white rays that are arranged in flat-topped corymbiform arrays, emerging in the late summer through fall. Other distinguishing characteristics include its serpentine stems and sharply serrated narrow heart-shaped leaves. The white wood aster is sometimes used in cultivation in both North America and Europe due to it being quite tough and for its showy flowers. Wikipedia →
Growing & care
USDA PLANTS · TRY- Hardiness
- ≥ zone 5 derived from its U.S. range
- Lifespan
- Perennial
- Flower colour
- White AI AI image-analysis of community-science photos (~87% expert agreement) — not a botanical record
Wildlife & pollinators
How pollinator value is scored →✦ Bees specialist-bee host · 23 bee visitors
Specialist native bees depend on it.
Some native bees are pollen specialists (oligolectic) — they raise young only on pollen from particular plant genera. Eurybia is a recorded specialist-bee host, so losing it can mean losing the bee that relies on it.
23 native & managed bee species are documented visiting White Wood Aster — the 12 most-recorded:
Wildlife & visitors 15 nectaring
Open records of who else uses White Wood Aster — a generalist food-web signal, kept separate from the keystone Ecological Value.
15 adult butterfly & moth species are recorded nectaring at its flowers — the most-recorded:
Across 261 U.S. vegetation-survey plots that recorded White Wood Aster, these catalog species turned up most often in the same plot — a real field co-occurrence signal, not a planting prescription.
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 (20) 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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