Opuntia Mill.

Leaves absent or if present then reduced and terete. Flowers sessile Opuntia
Stem segments mostly less than 4 cm wide and 10 cm long. Areoles with white hair-like spines and 1–4 stout spines up to 3 cm long. Drier areas. Introd. from S. America. Tiger Pear Opuntia aurantiaca
Stem segments mostly more than 5 cm wide and 10 cm long