Rock Spirea

rock_spireaThis very low-growing, matted shrub grows in carpets up to three feet wide as it creeps over rocks. The plant often grows on vertical surfaces and hangs by its roots, which cling to cracks in the rock. It produces many spike-like clusters of white flowers with whiskery stamens resembling small bottle-brushes that held about 4 inches above its small, blue-green leaves. Blooms in August and September.