Summary[edit] Description: Penstemon albomarginatus (whitemargin beardtongue). A few miles west of Pisgah Crater, slightly south of Highway 40, Barstow area, Mojave Desert, Califonia. Date: 7 May 2010, 16:16. Source: Penstemon albomarginatus. Author: John Game. . Description: British photographer. Work period: after 1965. Work location: United States, Australia, Polynesia, Fiji, United Kingdom, Switzerland. John Game from Berkeley, United States.