Maize (called corn in North America) is a fascinating plant. It is an annual grass whose female inflorescence is an axial raceme (the cob) of spikelets (becoming grains, a.k.a. kernels), each with a long, silky style protruding from a spathe (the husk). There is always an even number of spikelets, ranging from 8-32, depending on cultivar, and usually just one or two cobs per plant. The male flower is a tassel on the top of the plant. Pollen gets from the tassels to the silky styles by wind and gravity, not insects. The seed heads (cobs or ears) are larger than in any other species of grass. Some kinds of maize produce ears as long as 24 in (60 cm); another kind has tiny ears no longer than an inch (2.5 cm). There are literally thousands of maize cultivars. Different cultivars of maize have been developed for increased sugar content, increased starch content, greater size (up to 20 ft, or 6 m tall), smaller size (as little as 2 ft or 60 cm tall), earlier maturity, greater productivity and for popping. There are ornamental cultivars that produce colored kernels and colored husks. And, of course, Monsanto has given the world a whole slew of different types of "Roundup Ready Corn" which are immune to Roundup, herbicide, and so can be harmlessly drenched with the weed killer.
Zea mays Plant Profile - Floridata, http://www.floridata.com/Plants/Poaceae/Zea%20mays/1061 (accessed January 27, 2017).