Yellowstone sand verbena

Description

Abronia ammophila, the Yellowstone sand verbena, or Wyoming sand verbena, is a plant unique to Yellowstone National Park lakeshores and is endemic to the park. Part of the "Four o'clock" family (Nyctaginaceae), the abronia ammophila is best suited in sandy soils and lake shores. The presence of a sand verbena on the Yellowstone Plateau is surprising because of the high elevation (approximately 7,740 feet, or 2,360 meters) and long, cold winters. Yellowstone sand verbena is a member of a New World plant family that typically lives in warmer climates such as deserts and tropical areas. The genus Abronia includes about 30 species that primarily occur in warmer areas of the western United States and Mexico. Some botanists speculate that the thermal activity in Yellowstone has made it possible for a sand verbena to survive the harsh winters here and slowly evolve into a species that is adapted to this climate. In recent surveys, botanists have located four populations of Yellowstone sand verbena, but very little is known about its life history and biology. For example, the plant is represented as an annual in the scientific literature, although it is actually a perennial that overwinters underground as a large root system. No one currently knows how the plant is pollinated (though it is believed they are pollinated by insects), how the seeds are transported, or how long the seeds survive. Abronia, the sand-verbenas or wild lantanas, is a genus of about 20 species of annual or perennial herbaceous plants in the family Nyctaginaceae. Despite the common names, they are not related to Verbena (vervains) or lantanas in the family Verbenaceae. They are closely allied with Tripterocalyx. They are native to western North America, from Alberta and Saskatchewan, Canada, south to west Texas, California, Baja California and central Mexico, growing on dry sandy soils. Abronia macrocarpa, a Texas endemic, is protected under the Endangered Species Act. Abronia ammophila, the Yellowstone sand verbena, is a plant unique to Yellowstone National Park's lakeshores and is endemic to the park. Only a few species are widespread, and many are quite rare. They make very attractive garden plants for hot, dry sandy sites.