The ice cream bean tree is a legume, just as pole beans, peanuts, and peas are. Although they are all in different taxonomic families, they share some common traits. All of them, for example, feature seed pods that open along a seam. They all also have structures called root nodules, which allows them to add nitrogen to the soil in which they're grown. For this reason, they are highly prized in agricultural plans that feature crop rotation.