Research with the Basye Rose Breeding and Genetic Program at Texas A&M University has developed rose populations to use to study the genetic nature of leaf, stem, and several other rose traits. The rose populations are from the backcross of Rosachinensis`Old Blush' to WOB (interspecific hybridization of the diploid parents Rosawichuariana `Basye's Thornless' and `Old Blush'). The qualitative trait of presence of stem prickles and the quantitative traits of stem prickle density and leaflet number were observed in three field locations. Two locations are in College Station, Texas, and one location in Overton, Texas. The qualitative trait of presence of stem prickles supports the reported monogenic modes of inheritance. The presence of stem prickles (dominant) had a segregation ratio of 1:1 for prickles: no prickles. Prickle density and leaflet number demonstrated a quantitative mode of inheritance. For prickle density the genotype was significant and environment was nonsignificant. For leaflet number the genotype/generation was significant and environment was nonsignificant. This shows that genotype influences prickle density and leaflet number expression. The genotype by environment interaction was nonsignificant for all traits.