Mojave Aster in Red Rock Canyon State Park, California, USA.
Russian sage, Perovskia 'Blue spire', Side view of several white stems with feathery silver leaves and sparse, furry, blue purple flowers, creating a transparent effect.
Gaura, Gaura lindheimeri, Side view of several slender stems with white flowers from pink red sepals and long stamens, sparse flowering creates a transparent effect.