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Hydrophyllaceae family

Star Phacelia Phacelia stellaris

Native Specialist-bee host
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).

Star Phacelia is an annual wildflower native to the lower 48 states. It blooms Mar – Apr. A host for pollen-specialist native bees.

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
Cold hardiness (derived) — Hardiness
Hardiness
≥ zone 11 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 · Mar – Apr — 27 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 ~3 caterpillar species

Phacelia supports ~3 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 Phacelia in North America, including:

Annaphila ida · owlet moth Annaphila pseudoastrologa · owlet moth Annaphila vivianae · owlet moth Areniscythris brachypteris Baptarma felicita · owlet moth Clepsis fucana · leafroller moth
+ 8 more species →
Ethmia albistrigella Ethmia brevistriga Ethmia coquillettella Ethmia macelhosiella Ethmia nadia Ethmia semilugens Ethmia timberlakei Ethmia zelleriella · Zeller's Ethmia 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).
✦ Bees specialist-bee host · 20 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. Phacelia is a recorded specialist-bee host, so losing it can mean losing the bee that relies on it.

Xerces pollinator conservation →

20 native & managed bee species are documented visiting Star Phacelia — the 12 most-recorded:

Andrena medionitens · mining bee Andrena vicinoides · mining bee Anthidium clypeodentatum Anthidium collectum Anthidium emarginatum Anthidium palliventre
+ 6 more bees →
Anthidium tenuiflorae Anthophora urbana · digger bee Apis mellifera · Honey Bee Bombus californicus · California Bumble Bee Bombus centralis · Central Bumble Bee Bombus flavifrons · Yellow Head Bumble Bee
Specialist hosts from Smith et al. 2024. Visitor records (observations, not exhaustive) from Noori et al. 2026 (CC BY 4.0) · GloBI →
Wildlife & visitors 2 nectaring

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

2 adult butterfly & moth species are recorded nectaring at its flowers:

Aglais milberti · Milbert's Tortoiseshell Plebejus saepiolus
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.
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] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts · Smith et al. 2024 (CC BY)
[09] Conservation rank — NatureServe Explorer (CC BY)
[10] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[11] Wildlife & visitors — GloBI — Global Biotic Interactions (CC0)
[13] Flower-visitor value (derived) — Noori et al. 2026 (CC BY 4.0) · GloBI
[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
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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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