The Latin name for this species is mays and maize is the correct title for this group of plants. The plants many of us grow for corn on the cob, or “sweet corn” as it is sometimes called, is Z. mays ssp. rugosa, and was cultivated for its high sugar content. Many varieties of maize are grown for dried, fully mature seed, which is eaten as a grain, but sweet corn is picked before the seeds mature fully, before its sugars convert back into starch. This is why fresh corn must be eaten fairly quickly after harvest, before it degrades and becomes starchy. Many hybrids have been developed that retain their sweetness for longer periods, mature uniformly, and ship well.