Calcium-oxalate crystals and crystal cells in determinate root nodules of legumes.

Early reports of the presence of calciumoxalate crystals in the cortices ofPhaseolus vulgaris root nodules have been confirmed. Crystals were found in all six genera examined (Cajanus, Desmodium, Glycine, Lespedeza, Phaseolus, Vigna) that have determinate nodules and export ureides. They were absent from six genera examined that have indeterminate nodules and export amides. The possible physiological significance of these structures is discussed.