Flower profile

Purple owl's-clover

Castilleja exserta

Native in the lower 48

Purple owl's-clover is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 2 states, and across the U.S. it's most often seen in bloom in March–June.

5states

2of our state lists

17,500U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Arizona, California

Quick look

Castilleja exserta is a species of plant in the genus Castilleja which includes the Indian paintbrushes. Its common names include purple owl's clover, escobita, and exserted Indian paintbrush.
From Wikipedia's article Castilleja exserta, CC BY-SA 4.0.

It belongs to the Orobanchaceae family. ^iNaturalist
USDA PLANTS describes it as an herb (forb) with a annual life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as native in the lower 48 states and records it in 5 states. ^{USDA PLANTS}
NatureServe lists it as native to California and Arizona. ^NatureServe
In California, most iNaturalist sightings of it in flower come in March–June. ^iNaturalist
In Arizona, most iNaturalist sightings of it in flower come in February–May. ^iNaturalist
iNaturalist has 15,302 research-grade sightings of it in California, ranking #45 among the 110 flowers on our California list. ^iNaturalist
iNaturalist has 2,193 research-grade sightings of it in Arizona, ranking #43 among the 109 flowers on our Arizona list. ^iNaturalist

Purple owl's-clover gift ideas

Handmade purple owl's-clover gifts from independent makers.

🌱 Sample spot. Handmade gift picks from independent shops will appear here once our shop partnership is approved. These cards are placeholders, not real products.

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Purple owl's-clover art print
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Purple owl's-clover greeting card
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Purple owl's-clover mug
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Purple owl's-clover earrings
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Purple owl's-clover embroidery pattern
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Purple owl's-clover sticker
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When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (2,766 records)

Bloom time in each of our 2 states

State	Type	Peak bloom	Sightings*
California	Native	March–June	15,302
Arizona	Native	February–May	2,193

Conservation status

Federal (U.S. ESA): Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. ^{USFWS ECOS}
NatureServe global: G4 Apparently secure worldwide. ^NatureServe
California: Not listed Not on California state-listed endangered, threatened and rare plants (14 CCR § 670.2), per CDFW's CNDDB list (July 2026). NatureServe: SNR, not yet ranked in California. ^{CNDDB listed plants (July 2026)}
Arizona: Not listed Not on Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025). NatureServe: SNR, not yet ranked in Arizona. ^{AAC R3-3 App. A}
Rare elsewhere: No other U.S. state ranks it S1, S2, SH or SX.

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsNot well documented

It isn't on the ASPCA plant list.

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records purple owl's-clover in 5 states.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Arizona, California, Hawaii, Massachusetts, New Mexico.

California counties with USDA records: Alameda, Amador, Butte, Calaveras, Colusa, Contra Costa, El Dorado, Fresno, Glenn, Humboldt, Inyo, Kern, Kings, Lake, Los Angeles, Madera, Marin, Mariposa, Mendocino, Merced, Monterey, Napa, Nevada, Orange, Placer, Riverside, Sacramento, San Benito, San Bernardino, San Diego, San Francisco, San Joaquin, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Solano, Sonoma, Stanislaus, Sutter, Tehama, Tulare, Tuolumne, Ventura, Yolo.

Arizona counties with USDA records: Gila, Graham, Maricopa, Mohave, Pima, Pinal, Yavapai.

More California flowers

Warrior's plume

Pedicularis densiflora

Native

🌼 Blooms in CA: January–April

Felt paintbrush

Castilleja foliolosa

Native

🌼 Blooms in CA: February–June

Wholeleaf paintbrush

Castilleja integra

Native

🌼 Blooms: April–September

Sources

USDA, NRCS. PLANTS Database, profile CAEX14.
iNaturalist, Castilleja exserta: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Castilleja exserta (lead quoted under CC BY-SA 4.0).
California: California state-listed endangered, threatened and rare plants (14 CCR § 670.2), per CDFW's CNDDB list (July 2026).
California: California noxious weed species (3 CCR § 4500).
Arizona: Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025).
Arizona: Arizona prohibited noxious weeds (Ariz. Admin. Code R3-4-245).
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Castilleja exserta (global and state ranks).
Edibility and toxicity: no source found (marked "not well documented").
Photo: Gail A Baker via iNaturalist · CC BY 4.0 · resized.