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Ranunculaceae family

Tall Thimbleweed Anemone virginiana

Native

Tall Thimbleweed is a perennial wildflower native to Canada and the lower 48 states. It blooms May – Jul.

More about this plant

Anemone virginiana is an upright growing herbaceous species of flowering plant in the buttercup family Ranunculaceae. It is a perennial that grows 30–80 centimetres (12–31 in) tall, flowering from May until July. The flowers are white or greenish-white. After flowering, the fruits are produced in dense rounded thimble-shaped spikes 15–35 millimetres (0.59–1.38 in) long and 12 millimetres (0.47 in) wide. When the fruits, called achenes, are ripe they have gray-white colored, densely woolly styles, that allow them to blow away in the wind. The leaf structure is whorled halfway up the stem and each individual leaf appears to be deeply cut. It is native from eastern North America, where it is found growing in dry or open woods. This plant can be found in 38 out of the 50 states in the United States and is located anywhere from Maine to Minnesota going west, and found as far south as Georgia and Louisiana. Wikipedia →

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
Cold hardiness (derived) — Hardiness
Hardiness
≥ zone 4 derived from its U.S. range
Size & form
Sources · Size & form
USDA PLANTS — Lifespan
TRY Plant Trait Database (CC BY 4.0) — Foliage
McKenzie et al. 2025 — community-science image analysis (MIT) — Flower colour
Lifespan
Perennial
Foliage
Broadleaf
Flower colour
White AI AI image-analysis of community-science photos (~87% expert agreement) — not a botanical record
In the garden
Herb layer — Sits in the herb of a layered food forest or polyculture.Open guide →
derived roles
AI = read by an AI vision model · DERIVED = a computed estimate, not a direct measurement. The “How we know this” section below details each.
The garden year bloom → fruit → fall colour
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F
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J
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Bloom
Bloom (the flower's colour)
Bloom · May – Jul — 90 obs · USA-NPN — Nature's Notebook (CC BY 4.0)
Species characteristics from USDA PLANTS (public domain) + TRY (CC BY) — general guidance, not a guarantee for your exact site. Deer "browsing" is documented palatability, not a deer-proof claim.

Wildlife & pollinators

How pollinator value is scored →
❧ Caterpillar hosts ~1 caterpillar species

Anemone supports ~1 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 Anemone in North America, including:

Keystone count (genus-level) from Warren II 2026 (CC0) · Tallamy host-use records. Named species (a documented Nearctic sample, not exhaustive) from NHM HOSTS (CC0).
✦ Bees 2 bee visitors

2 native & managed bee species are documented visiting Tall Thimbleweed :

Visitor records (observations, not exhaustive) from Noori et al. 2026 (CC BY 4.0) · GloBI →
Species thumbnails re-hosted from iNaturalist — Creative Commons, credited per image (hover for credit). Click any species to see it on iNaturalist. Not exhaustive; many taxa have no openly-licensed photo yet.
How we know this (4) Methods & honest limits
Leaf build Direct fact

We read each species’ measured specific leaf area (leaf area per unit dry weight) from the Global Spectrum dataset and band it: thin & fast (high SLA), medium, or thick & tough (low SLA). The global median is about 10 mm²/mg.

Honest limits: A species-mean from pooled measurements — individual plants vary with light and site. A broad strategy signal, not a precise per-plant figure.

Díaz, S. et al. (2022) The global spectrum of plant form and function: enhanced species-level trait dataset. Scientific Data 9:755.
Photosynthesis Direct fact

A recorded categorical fact: each species is tagged C3 (standard), C4 (heat/water-efficient) or CAM (succulent, night-time CO₂ uptake) — or a facultative combination. We only show a trait card for the noteworthy C4/CAM cases; C3 is the unremarkable majority, kept in the data but not surfaced as a card.

Kattge, J. et al. TRY plant trait database — Categorical Traits Dataset (2012).
Climate niche (heat tolerance & native rainfall) Derived

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.

Realized-niche / climate-envelope approach (Pearson & Dawson 2003; Soberón 2007). Climate: NOAA NCEI nClimDiv county normals (1991–2020).
Flower colour Derived

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.

McKenzie, P., Berardi, A.E., Hopkins, R. (2025). flower_color_phenology (MIT).
Derived values are computed from open data by a published method — labelled, cited, and never shown as a direct observation. Full methodology →
Sources for this entry (25) Open & cited
[01] Scientific name & family — USDA PLANTS (DwCA, Zenodo 17903503)
[02] Growth habit & duration — USDA PLANTS (DwCA, Zenodo 17903503)
[03] Native status & distribution — USDA PLANTS (DwCA, Zenodo 17903503)
[04] Common name — USDA PLANTS (via GBIF)
[05] Invasive / introduced status — USDA PLANTS (DwCA, Zenodo 17903503) — native status
[06] Wetland indicator — USACE National Wetland Plant List (2022)
[08] Description — Wikipedia (CC BY-SA)
[09] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[11] Conservation rank — NatureServe Explorer (CC BY)
[13] Functional traits — TRY Plant Trait Database (CC BY 4.0)
[14] Photosynthetic pathway — TRY Plant Trait Database (CC BY 4.0)
[15] Climate niche — Derived — realized climate niche from U.S. county occurrences (GBIF) × NOAA NCEI county climate normals 1991–2020 (public domain)
[16] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[22] Flower-visitor value (derived) — Noori et al. 2026 (CC BY 4.0) · GloBI
[23] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[24] Caterpillar species — NHM HOSTS (CC0)
[25] County range — GBIF Open Data — open-licensed occurrences (CC0/CC-BY) → county
Spot an error or have a better photo? Every field links to its source, and the whole dataset is open.
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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