

Low Rough Aster Eurybia radula
Low Rough Aster is a perennial wildflower native to Canada, the lower 48 states, and Saint-Pierre & Miquelon. It blooms Jul – Sep. A host for pollen-specialist native bees.
More about this plant
Eurybia radula, commonly known as the low rough aster or rough wood aster, is an herbaceous perennial in the family Asteraceae. It is native to eastern North America where it is present from Newfoundland and Labrador in the far northeast of Canada, west to Ontario and south to Kentucky and Virginia in the United States. The low rough aster is also present on the French overseas territory of St. Pierre and Miquelon just south of Newfoundland. It typically grows in wet soils in a wide variety of habitats from bogs and fens to creek shores to ditches. Although it is not considered threatened over most of its distribution, it is imperiled or possibly extirpated over much of its range in the United States. Its flower heads emerge in the late summer to early fall and show pale blue-violet rays with yellow centres. Wikipedia →
Growing & care
USDA PLANTS · TRY- Hardiness
- ≥ zone 5 derived from its U.S. range
- Lifespan
- Perennial
- Flower colour
- Purple 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
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.
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 (16) 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).
Loading…
BibTeX
Loading…