L.D. Benson. 1969. Native Cacti of California 93.
Cylindropuntia wolfii is found in flats and rocky hillsides in the Sonoran Desert of far southern California and adjacent Baja California, Mexico. C. wolfii is a densely-branched, erect shrub growing to approximately 1.5 m tall. The firmly-attached stems range from 6 to 40 cm long by 2.5 to 4 cm wide. The areoles contain 12 to 25 gold to pale brown spines that age dark brown with yellow to pale brown sheaths. The flowers range from greenish-yellow through orange, to dark burgundy red. The filaments are red, the style is pink to red, at least distally, and the stigmas are cream. The fruits are dry and densely spiny.
C. wolfii is one of only four known Cylindropuntia species that is both hexaploid (2n = 66) and gynodioecious, having some individuals with perfect flowers and some individuals with pollen-sterile flowers. The other species with this combination of characteristics are C. chuckwallensis, C. sanfelipensis, and C. calmalliana. While none of these four species are particularly similar morphologically, they all share the flower color variation from yellow to orange to dark red, and all have red filaments and pink to red styles. Future genetic work should help elucidate the evolutionary relationships between these species.
C. wolfii is included in the California Native Plant Society Inventory of Rare and Endangered Plants on list 4.3 (limited distribution).