Penstemon caesius
San bernardino beardtongue
(c) Lynn Sweet, some rights reserved (CC BY), uploaded by Lynn Sweet · licence
Family: Plantaginaceae · Type: Subshrub · Native
Penstemon caesius (San bernardino beardtongue) is a native California subshrub in the Plantaginaceae family, recognized by subshrub habit, glaucous coating, and petioled rounded leaves.
San bernardino beardtongue is a California native shrub found in southern Sierra Nevada, San Gabriel Mountains, and San Bernardino Mountains in rocky ridges and open conifer forest and alpine communities at elevations of 1,800 to 3,400 meters. Flowering from June to August, this plant produces purple-blue flowers 15 to 23 millimeters long with a hairy flower floor and glandular exterior. Growing 20 to 80 centimeters tall with a subshrub form and glaucous, glabrous herbage, it has an upright, somewhat scapose structure. Its leaves are primarily basal, with widely obovate to round blades 15 to 43 millimeters long, attached to slender petioles and featuring entire margins. Its distinctive purple-blue flowers feature a calyx 3.7 to 7.5 millimeters long with lanceolate or ovate lobes, creating a striking appearance in alpine and high-elevation mountain environments.
Identification and appearance
Key characters: 36 sympatric species; subshrub habit, glaucous coating, and petioled rounded leaves
Habitat and range
Habitat: Rocky ridges and slopes in open conifer forest and alpine communities
Elevation: 1800-3400 m
California counties: Tulare, San Bernardino, Kern, Los Angeles, Inyo, Fresno
Bloom period
Penstemon caesius blooms Jun-Aug.
How to tell it apart
vs Epilobium: Penstemon has tubular two-lipped flowers with five stamens; Epilobium has four-petaled open flowers with eight stamens.; vs Keckiella: Penstemon is herbaceous and dies back; Keckiella has persistent woody stems year-round.; vs Salvia: Penstemon has five stamens (one sterile); Salvia has only two fertile stamens and square stems.; vs Ipomopsis: Penstemon has two-lipped tubular flowers; Ipomopsis has star-shaped flowers with five equal lobes.; vs Antirrhinum: Penstemon has a sterile stamen visible inside; Antirrhinum has only four stamens, none sterile.
Frequently asked questions
Is Penstemon caesius native to California?
Yes. Penstemon caesius is native to California (recorded as native).
When does Penstemon caesius bloom?
Penstemon caesius blooms Jun-Aug.
Where in California does Penstemon caesius grow?
Penstemon caesius occurs in Tulare, San Bernardino, Kern, Los Angeles, Inyo, Fresno, at elevations of 1800-3400 m.
What plant family does Penstemon caesius belong to?
Penstemon caesius is in the Plantaginaceae family, genus Penstemon.
What habitat does Penstemon caesius grow in?
Penstemon caesius grows in Rocky ridges and slopes in open conifer forest and alpine communities.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
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.