PlantKey Open ecological atlas
Planner
Home / Browse / Ceanothus / Mason's Ceanothus
iNaturalist — CC, credited & licensed per image
Rhamnaceae family

Mason's Ceanothus Ceanothus masonii

Native
Early-season nectar — Flowers in a late-winter / early-spring window when few other plants in our catalog bloom — valuable early forage for pollinators (relative to our catalog's bloom coverage).

Mason's Ceanothus is a perennial shrub native to the lower 48 states. It blooms Mar – Apr.

More about this plant

Ceanothus masonii is a species of shrub in the buckthorn family, Rhamnaceae, known by the common name Mason's ceanothus. It is endemic to Marin County, California, where it is known only from an area near Bolinas on the Point Reyes National Seashore. It grows in the coastal chaparral on the windblown bluffs. Wikipedia →

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
USDA PLANTS — Lifespan
TRY Plant Trait Database (CC BY 4.0) — Foliage
Lifespan
Perennial
Foliage
Evergreen broadleaf
In the garden
Shrub layer — Sits in the shrub 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 · Mar – Apr — 17 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 ~45 caterpillar species

Ceanothus supports ~45 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 strong genus.

Recorded feeding on Ceanothus in North America, including:

Acanthopteroctetes unifascia Acleris hastiana · leafroller moth Acronicta lepusculina · Cottonwood Dagger Moth Aethaloida packardaria · geometer (inchworm) moth Anacamptodes fragilaria · geometer (inchworm) moth Anavitrinella pampinaria · Common Gray
+ 8 more species →
Ancylis columbiana · leafroller moth Ancylis semiovana · leafroller moth Ancylis simuloides · leafroller moth Apodemia nais · Nais Metalmark Apodrepanulatrix liberaria · geometer (inchworm) moth Apodrepanulatrix litaria · geometer (inchworm) moth Archips argyrospila · Fruit-Tree Leafroller Moth Argyrolacia bifida · twirler 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).
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 (16) 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 — Warren II 2026 (CC0) · Tallamy host-use counts
[10] Conservation rank — NatureServe Explorer (CC BY)
[12] Photosynthetic pathway — TRY Plant Trait Database (CC BY 4.0)
[13] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[14] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[15] Caterpillar species — NHM HOSTS (CC0)
[16] 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…