One reason for optimism is that these dually capable plants already exist in nature. Clusia pratensis is what is known as a facultative CAM.

These results suggest a molecular basis for the classical concept of ‘facultative heterochromatin’ formation to silence blocks of genes as cells specialize.

That proved the North American pit vipers reproduced without a male, a phenomenon called facultative parthenogenesis that has previously been found only in captive species.