Taxonomic and Agronomic Variation in Agropyron spicatum and Agropyron inerme

Abstract

The main morphological distinction between bluebunch wheatgrass and beardless wheatgrass is the presence of geniculate awns in the former and the absence of awns in the latter. Open pollinate progenies of plants classified as either A. spicatum or as A. inerme segregated clearly for this trait. This indicates the mere presence or absence of awns does not afford reproductive isolation; thus, the species designation is questionable. In addition, variation for rhizomes was detected in the progenies of bunch type plants, but segregation was not clear cut. Significant variation among progeny means for forage yield was also detected. There is apparent, real potential for varietal development, but care must be exercised in mixing awned and awnless types.