Rhamnus purshiana
Cascara · also Cascara sagrada, Cascara buckthorn, Pursh's buckthorn
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This species is native to western North America, spanning from southern British Columbia to central California and eastward to northwestern Montana. It is typically a shrub or small tree, known for its bark, which was historically used as a laxative. It is considered a good plant for attracting wildlife, especially birds.
Where it grows
Trees in each city's inventory, with the share of that city's named trees this species accounts for.
- 260.01%—7.5 in
- 130.08%22 yr9.1 in
Traits
- Foliage
- Deciduous
- Mature height
- 20–40 ft
- Canopy spread
- 10–30 ft
- Water needs
- Moderate
- Wildlife value
- High
- Blooms
- Mar, Apr, May
Trunk diameters across every city: median 8.0 in, mean 8.5 in, 90th percentile 13 in. Measured at breast height, as published by each inventory.
Native range
Terrestrial ecoregions where this species is native. Trees in the dataset mostly stand well outside it.
Temperate Conifer Forests
- Alberta-British Columbia foothills forests
- British Columbia coastal conifer forests
- Central British Columbia Mountain forests
- Central-Southern Cascades Forests
- Northern California coastal forests
- Northern Rockies conifer forests
Mediterranean Forests, Woodlands & Scrub
- California coastal sage and chaparral
- California interior chaparral and woodlands
- California montane chaparral and woodlands
Temperate Grasslands, Savannas & Shrublands
- California Central Valley grasslands
- Montana Valley and Foothill grasslands
Other Rhamnus in the catalogue
5 of the top 2,000 species are in this genus.
