Cylindropuntia arbuscula forms hybrids with C. leptocaulis in south-central Arizona; those hybrids have narrow, obscurely tuberculate stems and reddish fruits nearly the size of those of C. arbuscula and chromosome number of 2n = 55. Hybrids between C. arbuscula and C. spinosior [= C . ×neoarbuscula (Griffiths) F. M. Knuth] have large green fruits, which often split open, and on stem segments distal areoles that usually bear three or four spines to 2.5 cm. Hybrids between C. arbuscula and C. versicolor [= C . ×vivipara (Rose) F. M. Knuth] have large green fruits, which often split open, and distal stem segment areoles that bear one or two spines to 1.5 cm.