Sugar snap peas were first developed in 1952 by cross-breeding snow pea with a mutant shell pea plant. Researchers hoped that the cross might counteract twisting and buckling seen in varieties at the time. With this cross, they developed a new class of snow pea.
Snap peas, like all other peas, are pod fruits. An edible-podded pea is less fibrous, and edible when young. Pods of the edible-podded pea, including snap peas, do not have a membrane and do not open when ripe.