Fructus (Latin for "fruits") is a legal term used in Roman law to describe goods naturally created by other property.
[4] There existed various exceptions to that general rule: The exact moment in time in which the ownership of fructus is ascertained differs in certain circumstances.
The core object's owner, good faith possessor or emphyteuta all take ownership of fructus in the moment they disconnect from the core object (separatio), while detentors and persons benefiting from ususfructus take ownership in the moment they collect the fructus (perceptio).
This was a very powerful servitude to give, as in most cases it left the owner only with bare ownership (nuda proprietas) of said property, therefore ususfructus was unable to be inherited or otherwise transferred to another person – it expired with the death of the user or at the time stipulated in the contract.
Importantly, such users may not impact or destroy the substance of the property in the course of their use and collection – a stipulation, cautio usufructuaria, was created for the purpose of preventing such abuses.