Sparganium emersum
European bur reed
(c) Suzanne Carriere, some rights reserved (CC BY) · licence
Family: Typhaceae · Type: Herb · Native
Sparganium emersum (European bur reed) is a native California herb in the Typhaceae family, recognized by medium-width keeled leaves and large fruiting structures.
European bur reed is a native perennial found in northern California coastal, Klamath Ranges, northern Coast Ranges, northern and central Sierra Nevada, San Bernardino Mountains, and Modoc Plateau regions in unpolluted freshwater habitats at elevations below 2,600 meters. Flowering in summer, this plant produces small greenish flower heads with distinct staminate and pistillate clusters arranged on emergent stems. Growing up to 75 centimeters tall when terrestrial or extending to 2 meters when aquatic, it develops distinctively triangular or keeled stems with flexible growth adaptations. Its leaves are notable for their wide blades measuring 5 to 13 millimeters across, typically three-angled and capable of varying dramatically in shape depending on water conditions. The fruit develops as an ellipsoid to fusiform structure approximately 3.5 to 4 millimeters long with a short 3 to 4 millimeter beak.
Identification and appearance
Key characters: 4 sympatric species; key features are medium-width keeled leaves and large fruiting structures
Habitat and range
Habitat: +- Unpolluted freshwater habitats
Elevation: < 2600 m
California counties: Humboldt, Trinity, Sierra, Modoc, Lassen, Siskiyou, Plumas, Nevada, Butte, Tuolumne, Mariposa, Inyo, Mendocino, Sonoma, Tehama
Outside California: to Alaska, northeastern North America, circumboreal
Bloom period
Sparganium emersum blooms Summer.
How to tell it apart
vs Typha: Sparganium has round spiky balls along the stem; Typha has cylindrical brown 'hot dog' spikes.; vs Ruppia: Sparganium has dense spherical flower heads; Ruppia has inconspicuous flowers on thread-like stems.; vs Myriophyllum: Sparganium has undivided ribbon-like leaves; Myriophyllum has feathery, finely-divided leaves.; vs Najas: Sparganium has spherical flower clusters on stems; Najas has tiny flowers hidden in leaf axils.; vs Callitriche: Sparganium has spherical flower heads on tall stems; Callitriche forms small rosettes at water surface.
Frequently asked questions
Is Sparganium emersum native to California?
Yes. Sparganium emersum is native to California (recorded as native).
When does Sparganium emersum bloom?
Sparganium emersum blooms Summer.
Where in California does Sparganium emersum grow?
Sparganium emersum occurs in Humboldt, Trinity, Sierra, Modoc, Lassen, Siskiyou, Plumas, Nevada and other counties, at elevations of < 2600 m.
What plant family does Sparganium emersum belong to?
Sparganium emersum is in the Typhaceae family, genus Sparganium.
What habitat does Sparganium emersum grow in?
Sparganium emersum grows in +- Unpolluted freshwater habitats.
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.