Populus tremuloides
Quaking aspen
(c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · licence
Family: Salicaceae · Type: Tree · Native
Populus tremuloides (Quaking aspen) is a native California tree in the Salicaceae family, recognized by round leaves, compressed petioles, and clonal habit are highly distinctive.
Quaking aspen is a California native tree found in the Klamath Ranges, northern Coast Ranges, Cascade Range, Sierra Nevada, San Bernardino Mountains, and Great Basin in streamsides, moist openings, and slopes within montane and subalpine forests at elevations of 900 to 3,150 meters. Flowering from April to June, this tree produces small catkins in delicate clusters. Growing up to 15 meters tall with a slender crown, it has distinctive green-white twigs and shiny winter buds. Its leaves have rounded to heart-shaped blades 2 to 4 centimeters long, with a green upper surface and glaucous undersurface, and finely toothed margins. Notably clonal, this tree spreads through extensive root systems, forming large interconnected groves across its mountain habitats.
Identification and appearance
Key characters: 5 sympatric species; round leaves, compressed petioles, and clonal habit are highly distinctive
Habitat and range
Habitat: Streamsides, moist openings, slopes in montane, subalpine forest, woodland, sagebrush steppe
Elevation: 900-3150 m
California counties: Mono, Trinity, Siskiyou, Fresno, El Dorado, Nevada, San Bernardino, Tuolumne, Modoc, Tulare, Inyo, Mariposa, San Diego, Plumas, Placer, Amador, Madera, Sierra, Los Angeles, Alpine, Lake, Shasta, Butte, Tehama, Mendocino, Calaveras, Lassen, Monterey, Alameda
Outside California: to Alaska, eastern North America, Mexico
Bloom period
Populus tremuloides blooms Apr-Jun.
How to tell it apart
vs Quercus: Poplar leaves flutter conspicuously on flat petioles; oaks have stiff leaves that don't flutter and produce acorns.; vs Salix: Poplar catkins hang downward like tassels; willow catkins stand upright or spread outward.; vs Pyrus: Poplars have catkins and cottony seeds; pears have showy white flowers and round pear-shaped fruits.; vs Platanus: Poplar bark is furrowed; sycamore bark peels in puzzle-piece patches revealing white inner bark.; vs Alnus: Poplar catkins are soft and pendulous; alder has woody cone-like structures that persist through winter.
Frequently asked questions
Is Populus tremuloides native to California?
Yes. Populus tremuloides is native to California (recorded as native).
When does Populus tremuloides bloom?
Populus tremuloides blooms Apr-Jun.
Where in California does Populus tremuloides grow?
Populus tremuloides occurs in Mono, Trinity, Siskiyou, Fresno, El Dorado, Nevada, San Bernardino, Tuolumne and other counties, at elevations of 900-3150 m.
What plant family does Populus tremuloides belong to?
Populus tremuloides is in the Salicaceae family, genus Populus.
What habitat does Populus tremuloides grow in?
Populus tremuloides grows in Streamsides, moist openings, slopes in montane, subalpine forest, woodland, sagebrush steppe.
Related species
Other California species in the same genus, family, or bioregion.
- Populus trichocarpa — Black cottonwood
- Populus alba — White poplar
- Populus angustifolia — Narrow-leaved cottonwood
- Populus fremontii subsp. fremontii — Alamo or fremont cottonwood
- Populus nigra — Black poplar
- Populus sp. — Cottonwood
- Salicaceae sp. — Willow family
- Salix alba — White willow
- Salix babylonica — Weeping willow
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.