Trichostema ruygtii
Napa bluecurls
(c) John Hibbard, some rights reserved (CC BY) · licence
Family: Lamiaceae · Type: Herb · Native
Conservation status: CNPS 1B.2
Trichostema ruygtii (Napa bluecurls) is a native California herb in the Lamiaceae family.
Napa bluecurls is a rare (CNPS 1B.2) California native annual found in southern North Coast Ranges and Inner North Coast Ranges in Napa County, growing in open areas with thin clay soils at elevations of 30 to 600 meters. Flowering from June to October, this plant produces blue to purple flowers with a distinctive curved corolla tube that sharply recurves near the throat. Growing up to 50 centimeters tall with stems covered in short, curved or long spreading hairs, some of which are glandular. Its leaves are lanceolate, 1 to 4 centimeters long, with prominent lateral veins near the base and a length about three times its width. The delicate blue flowers feature a lower lip 2 to 4.5 millimeters long, creating an elegant and intricate botanical display.
Identification and appearance
Key characters: 0 sympatric species - geographically isolated
Habitat and range
Habitat: Open areas, generally thin clay soils, possibly seasonally saturated
Elevation: 30-600 m
Bloom period
Trichostema ruygtii blooms Jun-Oct.
Conservation status
CNPS 1B.2
How to tell it apart
vs Salvia: Trichostema flowers have five equal lobes; sage flowers are distinctly two-lipped.; vs Lavandula: Trichostema stamens arch dramatically outward; lavender stamens stay hidden inside the flower tube.; vs Penstemon: Trichostema has square stems and opposite leaves; penstemon stems are round.; vs Lupinus: Trichostema flowers have five equal lobes; lupine flowers are pea-shaped with banner and keel.; vs Sairocarpus: Trichostema has four stamens visible arching out; snapdragons hide stamens inside closed throat.
Frequently asked questions
Is Trichostema ruygtii native to California?
Yes. Trichostema ruygtii is native to California (recorded as native).
When does Trichostema ruygtii bloom?
Trichostema ruygtii blooms Jun-Oct.
What plant family does Trichostema ruygtii belong to?
Trichostema ruygtii is in the Lamiaceae family, genus Trichostema.
Is Trichostema ruygtii rare or endangered?
Trichostema ruygtii carries California Rare Plant Rank 1B.2, state rank S2.
What habitat does Trichostema ruygtii grow in?
Trichostema ruygtii grows in Open areas, generally thin clay soils, possibly seasonally saturated.
Related species
Other California species in the same genus, family, or bioregion.
- Trichostema simulatum — Siskiyou bluecurls
- Trichostema sp. — Blue curls
- Trichostema austromontanum — San jacinto bluecurls
- Trichostema austromontanum subsp. austromontanum
- Trichostema austromontanum subsp. compactum — Hidden lake bluecurls
- Trichostema lanatum — Woolly blue curls
- Acanthomintha duttonii — San mateo thornmint
- Acanthomintha ilicifolia — San diego thornmint
Sources: Jepson eFlora · CalPhotos · CDFW CNDDB
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.