

Hairy Bird's-beak Cordylanthus pilosus
Hairy 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 pilosus is a species of flowering plant in the family Orobanchaceae known by the common name hairy bird's beak. It is endemic to the mountain ranges and foothills of northern California, where it grows in woodland and chaparral habitat, often on serpentine soils. There are three subspecies, each mainly limited to a different section of mountains. In general this annual herb is erect and branching, reaching a maximum height anywhere between 20 centimeters and 1.2 meters. It is purple-tinted gray-green in color and usually quite hairy in texture, the hairs sometimes associated with sticky glands. The branches have sparse tufts of small linear leaves. The flowers of the inflorescence have bracts which may be linear in shape or lobed, each lobe knobby or notched. The flower is up to 2 centimeters long and has a whitish pouch marked with yellow and purple enclosed in hairy sepals. Wikipedia →
Growing & care
USDA PLANTS · TRY- Hardiness
- ≥ zone 11 derived from its U.S. range
- Lifespan
- Annual
- Flower colour
- Brown AI AI image-analysis of community-science photos — lower-confidence (a more subjective call, often an inconspicuous flower); not a botanical record
Wildlife & pollinators
How pollinator value is scored →❧ Caterpillar hosts Documented caterpillar host
Recorded feeding on Cordylanthus in North America, including:
✦ Bees specialist-bee host · 7 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.
7 native & managed bee species are documented visiting Hairy Bird's-beak :
+ 1 more bees → ↑ show fewer
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 (17) 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…