"Blue Cascade" -- flowering Ceanothus tomentosus streams down a hillside, Del Dios Gorge, Escondido, California. April 2018.
The slope effect describes the distribution and density of plants based on where they grow – on a north-facing slope such as this one, just west of the Lake Hodges dam, exposure to the sun is limited and taller shrubs such as Ceanothus can grow dense and in abundance. When they flower in spring, their vivid blue is a feast for the eyes.