

Lyall's Angelica Angelica arguta
Lyall's Angelica is a perennial wildflower native to Alaska, Canada, and the lower 48 states. It grows to 6 ft and blooms Apr in full sun – part shade, with brown fruit.
More about this plant
Angelica arguta commonly known as Lyall's angelica is a species of angelica. It is native to western North America, where it grows in coniferous forests from British Columbia to Utah. This is a taprooted perennial herb growing an erect, hollow stem to heights between one and two meters. It produces large, somewhat triangular leaves made up of many toothed, pointed leaflets each up to 9 centimeters long. The top of the stout stem is occupied by an inflorescence in a compound umbel arrangement, with the webbed rays of the umbel up to 10 centimeters long each. The flowers are generally yellowish. Wikipedia →
Growing & care
USDA PLANTS · TRY- Sun
- Full sun – part shade
- Soil & moisture
- High moisture
- Soil pH
- 6.5–7.5
- Fertility need
- Medium
- Adapts to
- Medium (loam), Fine (clay)
- Hardiness
- USDA zone 6+
- Height
- 6 ft
- Spread
- None — clumping
- Growth rate
- Rapid
- Growth form
- Single crown
- Lifespan
- Perennial · moderate
- Foliage
- Broadleaf · coarse texture
- Active growth
- Summer
- Fruit
- Brown
- Flower colour
- White AI AI image-analysis of community-science photos (~87% expert agreement) — not a botanical record
- Propagate by
- Seed
- Seed starting
- No stratification needed
- Seeds ripen
- Summer seed-collection / harvest window
- In the trade
- Routinely available
- Resprouts if cut
- No
Sow timing keys off your local last- and first-frost dates.
Wildlife & pollinators
How pollinator value is scored →❧ Caterpillar hosts ~5 caterpillar species
Angelica supports ~5 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 Angelica in North America, including:
+ 7 more species → ↑ show fewer
✦ Bees 7 bee visitors
7 native & managed bee species are documented visiting Lyall's Angelica :
+ 1 more bees → ↑ show fewer
Wildlife & visitors 2 nectaring
Open records of who else uses Lyall's Angelica — a generalist food-web signal, kept separate from the keystone Ecological Value.
2 adult butterfly & moth species are recorded nectaring at its flowers:
Across 47 U.S. vegetation-survey plots that recorded Lyall's Angelica, 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 (33) 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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