What is the fruit called that grows on a cactus?

The fruit of the barrel cactus [Ferocactus spp] are small berries. They show up in summer. Their appearance is preceded by the plant's large, bell or funnel shaped flowers that tend towards violet or yellow. A barrel cactus also may be found in the Echinocactus genus. This type of barrel cactus is characterized by open faced flowers that range from golden yellow to purple red. The blooms aren't followed by fruits. Instead, they're succeeded by papery seedpods.