Bobich E. G., Vegetative reproduction, population structure, and morphology of Cylindropuntia fulgida var. mamillata in a desert grassland, International Journal of Plant Sciences, 2005, 166(1):97-104, doi: 10.1086/425665
A comparison of two stands of Cylindropuntia fulgida var. mamillata and greenhouse trials of fruit and segment rooting. It discusses how clonal recruitment depends on plant size, available space, ground cover and water supply.