The family leguminosae is now split into three families: leguminosae, fabaceae (aka papillionaceae)and mimosaceae. Books will refer to different names depending on when it was printed. Either way, both house certain bacteria within their roots which help fix nitrogen from the atmosphere (which plants cannot use) into nitrates (which plants can use) into the soil. This process is nitrogen fixation, and helps to replenish the amount of nitrogen in the soil. Hence, cover crops are often plants within this family (or these families).

Characteristics of Fabaceaa:

Pinnate leaves or bipinnate (rarely other leaf forms)
Regular or irregular flowers (Clitoria sp.) --> sweet pea flower shaped
seed pods usually one chambered

Wow talk about motivating one to look up something,,,,, very interesting indeed! Thanks Kenny!

Thanks for the update Kenny.The world of plants is constantly changing as new dicoveries are made.Are you planning to become a botanist?