PlantKey Open ecological atlas
Planner
Home / Browse / Cordylanthus / Slender Bird's Beak
iNaturalist — CC, credited & licensed per image
Scrophulariaceae family

Slender Bird's Beak Cordylanthus tenuis

Native Specialist-bee host

Slender Bird's Beak is an annual wildflower native to the lower 48 states. It blooms Jul – Sep. A host for pollen-specialist native bees.

More about this plant

Cordylanthus tenuis is a species of flowering plant in the family Orobanchaceae known by the common name slender bird's beak. It is native to the US states of California, Oregon, and Nevada, where it grows in woodland and forest. It erects a spindly stem which may exceed a meter in height with sparse narrow leaves a few centimeters long, and is sometimes sticky with glandular secretions. The plant is greenish and tinted with yellow or purple coloration. The stem branches at intervals and at the end of each branch is a cluster of one to several flowers. Each pocket-shaped flower is one to two centimeters long and about one wide, made up of fuzzy maroon lobes with white or yellow lips. Wikipedia →

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
Cold hardiness (derived) — Hardiness
Hardiness
≥ zone 9 derived from its U.S. range
Size & form
Sources · Size & form
USDA PLANTS — Lifespan
Lifespan
Annual
In the garden
Herb layer — Sits in the herb of a layered food forest or polyculture.Open guide →
derived roles
The garden year bloom → fruit → fall colour
J
F
M
A
M
J
J
A
S
O
N
D
Bloom
Bloom (the flower's colour)
Bloom · Jul – Sep — 391 obs · Herbarium specimens — Park et al. 2023 (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 Documented caterpillar host

Recorded feeding on Cordylanthus in North America, including:

Thessalia leanira · brush-footed butterfly ✦
Named species (a documented Nearctic sample, not exhaustive) from NHM HOSTS (CC0). ✦ = recorded on this exact species.
✦ Bees specialist-bee host · 5 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. Cordylanthus is a recorded specialist-bee host, so losing it can mean losing the bee that relies on it.

Xerces pollinator conservation →

5 native & managed bee species are documented visiting Slender Bird's Beak :

Anthidium edwardsii · Edwards' Wool-Carder Bee Megachile angelarum · leafcutter bee Bombus vosnesenskii · Vosnesensky Bumble Bee Megachile brevis · Common Little Leaf-Cutter Bee · ✦ specialist Megachile gentilis · leafcutter bee
Specialist hosts from Smith et al. 2024. Visitor records (observations, not exhaustive) from Noori et al. 2026 (CC BY 4.0) · GloBI → · ✦ = pollen-specialist bee (Smith et al. 2024)
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
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).
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 (17) 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
[07] Description — Wikipedia (CC BY-SA)
[08] Ecological value — GloBI · Smith et al. 2024 (CC BY)
[10] Conservation rank — NatureServe Explorer (CC BY)
[11] Climate niche — Derived — realized climate niche from U.S. county occurrences (GBIF) × NOAA NCEI county climate normals 1991–2020 (public domain)
[12] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[14] Bee specialists — Smith et al. 2024 (Zenodo, CC BY 4.0)
[15] Flower-visitor value (derived) — Noori et al. 2026 (CC BY 4.0) · GloBI
[16] Caterpillar species — NHM HOSTS (CC0)
[17] 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).

Citation

Loading…

BibTeX 
Loading…