Agropyron scribneri Vasey (spreading wheatgrass) is endemic to the Rocky Mountains of the Intermountain West. Each distinct population is widely separeated by valley and desert floors. It is morphologically similar to the hybrid between Agropyron trachycaulum (Link) Malte and Sitanion hystrix between Agropyron trachycaulum (Link) Malte and Sitanion hystrix (Nutt.) J. G. Smith as well as the hybrid, A. trachycaulum x A. scribneri. It appears that A. scribneri may have originated de novo from hybidization products of A. trachycaulum and S. hystrix. Agropyron scribneri appears to be morphologically similar to the population of S. hysterix with which it is associated. There is some fertility in the A. trachycaulum x S. hysterix hybrids, and back-crossing onto both A. trachucaulum and S. hysterix is common. Sterile backcross derivatives, (A. trachycaulum x S. hysterix) x S. hysterix, were found which possess characters similar to A. scribneri and which phenotypically resemble A. scribneri. These are considered to be stabilized hybrid segregants which indicate that the incipient formation of A. scribneri is in progress.
College and Department
Plant and Wildlife Sciences
BYU ScholarsArchive Citation
Pope, C. Lorenzo, "A study of the phylogenetic relationships of Agropyron scribneri, Agropyron trachycaulum, and Sitanion hystrix" (1972). Theses and Dissertations. 7959.