Natural Hybridization between the Cholla Cactus Species Opuntia spinosior and Opuntia versicolor
Abstract
The sexually reproducing cholla cactus species, Opuntia spinosior and O. versicolor, hybridize naturally in Arizona to produce hybrid swarms and segregating introgressive populations with a high degree of individual variation. The pattern of variation in these hybrid populations can be compared with that in populations derived from crossing of O. spinosior and O. fulgida, where the hybrids reproduce vegetatively rather than by seeds. The latter hybrid combination, in marked contrast to the former, results in clonal colonies with little or no observable individual variation.
