Do Waldsteinia and Obregonia contain the same number of species?
Obregonia Obregonia, the artichoke cactus, is a genus of cacti with a single species, Obregonia denegrii. The species is endemic to the state of Tamaulipas in Mexico.
Ostrea Ostrea is a genus of edible oysters, marine bivalve mollusks in the family Ostreidae, the oysters.