A single corn stalk grows several ears, which are the female bits of the plant, and has one tassel up top, which as you can guess is the male part. The tassel produces pollen, which is the semen of the plant world. Before those ears look anything like the thing you eat, they're essentially a hard cylinder covered in hundreds of unfertilized ovules. Each of these ovules grows a single silk, which reaches up and out of the top of the husk, where it dangles in the hopes of catching a bit of pollen on its little sticky hairs. If it does, the silk grows a pollen tube, enabling the male genes to travel towards the ovule and fertilize it. That fertilized ovule will grow into a single kernel.