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Scrophulariaceae family

Broomleaf Toadflax Linaria genistifolia

Broomleaf Toadflax is an introduced perennial herb, found in the lower 48 states. It grows to 1.0 ft.

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
Cold hardiness (derived) — Hardiness
Hardiness
≥ zone 5 derived from its U.S. range
Size & form
Sources · Size & form
TRY Plant Trait Database (CC BY 4.0) — Height · Foliage
USDA PLANTS — Lifespan
Height
1.0 ft
Lifespan
Perennial
Foliage
Broadleaf
In the garden
Herb layer — Sits in the herb of a layered food forest or polyculture.Open guide →
derived roles
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 ~5 caterpillar species

Linaria 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 for introduced plants — native genera typically support far more.

Recorded feeding on Linaria in North America, including:

Penstemonia clarkei · clearwing moth ✦ Calophasia lunula · Toadflax Brocade Charidryas gorgone · brush-footed butterfly Junonia coenia · Common Buckeye Lepipolys perscripta · owlet moth Rhodoecia aurantiago · owlet moth
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). ✦ = recorded on this exact species.
✦ Bees 9 bee visitors
Visitor records (observations, not exhaustive) from Noori et al. 2026 (CC BY 4.0) · GloBI →
Wildlife & visitors 53 birds · 7 nectaring

Open records of who else uses Broomleaf Toadflax — a generalist food-web signal, kept separate from the keystone Ecological Value.

7 adult butterfly & moth species are recorded nectaring at its flowers — the most-recorded:

Pieris rapae · Small White Macroglossum stellatarum · Hummingbird Hawk-Moth Polyommatus icarus · Common Blue Colias philodice · Clouded Sulphur Euptoieta claudia · Variegated Fritillary Hesperia pahaska · Pahaska Skipper
Interaction records (observations, not exhaustive) from GloBI → (CC0). Counts are distinct species; names are the most-recorded. Common names from Wikidata (CC0).
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 (1) Methods & honest limits
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).
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 (21) 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 — US-RIIS v2.0 (USGS)
[07] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[08] Conservation rank — NatureServe Explorer (CC BY)
[11] Functional traits — TRY Plant Trait Database (CC BY 4.0)
[12] Photosynthetic pathway — TRY Plant Trait Database (CC BY 4.0)
[13] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[14] Wildlife & visitors — GloBI — Global Biotic Interactions (CC0)
[18] Flower-visitor value (derived) — Noori et al. 2026 (CC BY 4.0) · GloBI
[19] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[20] Caterpillar species — NHM HOSTS (CC0)
[21] 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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