Mahonia nervosa, commonly known as Dwarf Oregon-grape or Cascade Oregon-grape, is a flowering plant native to the northwest coast of North America from southern British Columbia south to central California, with an isolated population inland in northern Idaho. It is especially common in second growth, Douglas-fir or Western Redcedar forests, making use of those pools of sunlight that intermittently reach the ground.
The plant was collected by Lewis and Clark during their famous expedition to the West before being described for science in 1813.
It is an evergreen shrub with short vertical stems, mostly under 30 cm, while the leaves reach higher, rarely up to 2 m tall. The leaves are compound, with 9-19 leaflets; each leaflet is strongly toothed, reminiscent of holly, and somewhat shiny, but less so than Tall Oregon-grape. The leaflets do not have a single central vein as in that species, but several veins arranged fan-like, branched from the leaflet base, hence the epithet nervosa. The flowers and fruit are like those of other Oregon-grapes; like them they are edible but just as sour.