Yellowstone Sand Verbena
Along the shore of Yellowstone Lake is the only place in the world that the species known as Yellowstone sand verbena grows. The presence of a sand verbena at 7,700 feet elevation in the northern Rockies is unexpected, as most members of this North American genus occur in the Southwest or along the Pacific Coast. One speculation by botanists is that the warmth provided by the geothermal activity in the area enabled a genus which had evolved in a warmer climate to gradually adapt to conditions in Yellowstone. Today, Yellowstone sand verbena (Abronia ammophila) tolerates the long, cold winters and uses the brief summer to bloom and reproduce.