albidum, using the mistaken Linnaean correction of John Mitchell's Penstemon and albidus from the Latin meaning 'somewhat white'. During the botanist John Fraser's 1807 trip to the United States he collected specimens and seeds for a plant he called Penstemon teretiflorus. This was listed in Catalogue of New and Interesting Plants Collected in Upper Louisiana, a book generally accepted as being written by Nuttall and published in 1813. However, it is accepted that this was in fact P. albidus more correctly described by Nuttall in 1817. Up until the year 1828 plants in Penstemon were sometimes classified as Chelone, as Kurt Sprengel did in 1825 when he described Penstemon albidus as Chelone albida in Systema Vegetabilium. The German botanist Christian Nees von Esenbeck described it as Penstemon viscidulus in 1821 and this later identification was not definitively resolved until David D. Keck published his paper Studies in Penstemon VI in 1938. The chromosome number for Penstemon albidus is 16 in diploid individuals. Habitat and Distribution Penstemon albidus is commonly found growing in silty, sandy loam, or gravelly soils. and they can be found grow from 300 to 1800 m in elevation. Its main habitat is open, dry prairies, but it also grows in juniper savannas in Colorado. Penstemon albidus is one of the widely distributed members of its genus, being native almost the entirety in the western great plains of North America. In the south it grows in north of West Texas and the Texas Panhandle. They also grow in the northeast of New Mexico and the west of Oklahoma and its panhandle. The range continues north into the western half of Kansas and the eastern plains of Colorado. The USDA Natural Resources Conservation Service PLANTS database (PLANTS) likewise records it throughout most of Nebraska and three of the westernmost counties of Iowa. White penstemons grow in the western third of Wyoming and almost all of Montana including valleys in the foothills of its mountains. It grows throughout North Dakota, much of South Dakota, and the western counties of Minnesota. In Canada its natural range is restricted to the southern portions of Alberta, Manitoba, and Saskatchewan, with the reported occurrences in Ontario suspected by Flora of North America to be introduced. Ecology The above ground growth of P. albidus is rarely eaten by grazing livestock. It increases in population in areas with grazing compared to nongrazed land, with the greatest