Acer glabrum
Mountain maple, Mountain Maple
(c) Caleb Catto, some rights reserved (CC BY), uploaded by Caleb Catto · licence
Family: Sapindaceae · Type: Shrub / Tree · Native
Acer glabrum (Mountain maple) is a native California shrub / tree in the Sapindaceae family, recognized by no sympatric species.
Mountain maple is a native shrub found in western North American mountain ranges in mixed conifer and montane forest habitats. Flowering from April to June, this plant produces small greenish-yellow flowers in terminal clusters that appear after its leaves emerge. Growing as a multi-stemmed shrub or small tree up to 6 meters tall, it develops a distinctive branching structure with smooth bark. Its leaves are uniquely three-lobed, typically with 3 to 22 sharp or rounded teeth along the outer edges, and display a pale green undersurface. The fruit features distinctive wing-like structures spreading at 70 to 120 degrees, creating an open, winged seed arrangement.
Identification and appearance
Key characters: Geographically isolated; no sympatric species
Habitat and range
California counties: Mariposa, San Bernardino, Inyo, Siskiyou, Shasta, Tuolumne, Plumas, Del Norte, Humboldt, Trinity, Tulare, El Dorado, Nevada, Fresno, Alpine, Amador, Tehama, Placer, Mono, Calaveras, Butte, Sierra, Riverside
How to tell it apart
vs Platanus: Maple fruits are paired helicopters; sycamore has hanging ball-like seed clusters and peeling bark.; vs Liquidambar: Maple fruits split into two wings; sweetgum has spiky round seed balls and star-shaped leaves with pointed lobes.; vs Quercus: Maple leaves have palmate veins radiating from base; oak leaves have pinnate veins branching from midrib.; vs Fraxinus: Maples have simple lobed leaves; ash has compound leaves with 5-9 separate leaflets arranged feather-like.; vs Morus: Maple fruits are dry winged samaras; mulberry produces fleshy blackberry-like fruits and has milky sap.
Frequently asked questions
Is Acer glabrum native to California?
Yes. Acer glabrum is native to California (recorded as native).
Where in California does Acer glabrum grow?
Acer glabrum occurs in Mariposa, San Bernardino, Inyo, Siskiyou, Shasta, Tuolumne, Plumas, Del Norte and other counties.
What plant family does Acer glabrum belong to?
Acer glabrum is in the Sapindaceae family, genus Acer.
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.