Name: Anonymous 2010-08-06 1:57
Legume plants are notable for their ability to "fix" atmospheric nitrogen (a process by which nitrogen in the atmosphere is converted into ammonia, whose molecule is one nitrogren atom and three hydrogen atoms, so you could say that nitrogen atoms are "fixed", i.e. attached, to hydrogen atoms), thanks to a symbiotic relationship with bacteria (rhizobia) found in root nodules of these plants.