Kalmia polifolia
Swamp laurel, bog laurel, Box Laurel
(c) Sam Beaumont, some rights reserved (CC BY) · licence
Family: Ericaceae · Type: Shrub · Native
Kalmia polifolia (Swamp laurel) is a native California shrub in the Ericaceae family, recognized by Relict species - represents a disjunct southern population of a primarily boreal genus.
Swamp laurel is a California native shrub found in the Klamath Ranges, North Coast Ranges, California Ranges, Sierra Nevada, and Warner Mountains in peat bogs, moist meadows, and rock crevices at elevations of 1,000 to 3,500 meters. Flowering from June to August, this plant produces delicate pink to rose-purple flowers in clusters with distinctive bell-shaped corollas 7 to 11 millimeters long. Growing as a low-spreading mat with ascending stems 10 to 70 centimeters tall, it forms dense ground-covering patches. Its leaves are distinctive, measuring 4 to 60 millimeters long and 3 to 25 millimeters wide, with a pale green to white undersurface and a fine, soft covering. The compact shrub produces small fruits 4 to 5 millimeters wide, nestled among its linear to ovate foliage.
Identification and appearance
Key characters: Relict species - represents a disjunct southern population of a primarily boreal genus
Habitat and range
Habitat: Peat bogs, moist meadows, rock crevices
Elevation: 1000-3500 m
California counties: Fresno, Mono, Tulare, Siskiyou, Inyo, Modoc, Plumas, Sierra, El Dorado, Humboldt, Tuolumne, Trinity, Madera, Amador, Placer, Shasta, Alpine
Outside California: northern North America
Bloom period
Kalmia polifolia blooms Jun-Aug.
How to tell it apart
vs Rhaphiolepis: Kalmia has fused petals with anther pockets; Rhaphiolepis has separate flat petals.; vs Phyllodoce: Kalmia flowers have anther pockets; Phyllodoce has simple bell flowers without pockets.; vs Rhododendron: Kalmia has stamens held in pockets; Rhododendron has free stamens in bell flowers.; vs Ceanothus: Kalmia has cup-shaped heath flowers; Ceanothus has tiny flowers in dense rounded clusters.; vs Prunus: Kalmia has fused petals forming cups; Prunus has 5 separate spreading petals.
Frequently asked questions
Is Kalmia polifolia native to California?
Yes. Kalmia polifolia is native to California (recorded as native).
When does Kalmia polifolia bloom?
Kalmia polifolia blooms Jun-Aug.
Where in California does Kalmia polifolia grow?
Kalmia polifolia occurs in Fresno, Mono, Tulare, Siskiyou, Inyo, Modoc, Plumas, Sierra and other counties, at elevations of 1000-3500 m.
What plant family does Kalmia polifolia belong to?
Kalmia polifolia is in the Ericaceae family, genus Kalmia.
What habitat does Kalmia polifolia grow in?
Kalmia polifolia grows in Peat bogs, moist meadows, rock crevices.
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.