The California interior chaparral and woodlands ecoregion forms an elliptical ring of hills and low mountains around California's Central Valley, stretching from Shasta Lake south toward Wheeler Ridge. Its biologically rich mosaic includes chaparral, grasslands, oak savannas and woodlands, serpentine communities, pine and montane conifer forests, riparian forests, and wetlands. The climate is Mediterranean, with warm, dry summers and mild, wet winters. Notably, it hosts the largest number of endemic mammals of any ecoregion in the U.S. and Canada, with the Alameda whipsnake as its flagship species; urban sprawl and rural development are leading threats.

At a glance

About the mediterranean forests, woodlands & scrub biome

Regions of hot, dry summers and mild, wet winters supporting drought-adapted shrublands — chaparral, maquis, fynbos — and open woodlands. Fire is a natural shaping force, and these climates hold extraordinary plant diversity and endemism.

National refinement sub-regions

Catalog plants suited to this ecoregion

Computed from each plant's stated USDA zone range against this ecoregion's USDA Plant Hardiness Zone Map 2023 (1991-2020 climatology) via ArcGIS FeatureServer published current zone range, with the CHELSA mid-century warming delta applied for the projection. Plants whose stated range falls outside both the current and projected zone end up dropped; the rest land in one of the three buckets below.

Collections for this ecoregion

Curated multi-plant collections whose members all fit this ecoregion's zone range — no won't-grow members smuggled in. Overall fit class shown per collection is the weakest link across its members.

Related ecoregions