List of nitrogen-fixing-clade families

The nitrogen-fixing clade consists of four orders of flowering plants: Cucurbitales, Fabales, Fagales and Rosales. This subgroup of the rosids encompasses 28 families of trees, shrubs, vines and herbaceous perennials and annuals. The roots of many of the species host bacteria that fix nitrogen into compounds the plants can use.

This keyword could refer to multiple things. Here are some suggestions: