I took this picture at the Montreal Botanical Gardens where to my delight they had a bed of cereal grains growing in the edible garden section. I love this place.
The name was too long to put in the title line so here it is: Sorghum bicolor gr. Saccharatum ‘Black African’.
The name gave me some clues to its usage and in looking it up I have discovered that it is indeed used to produce a sweetener called sorghum syrup. The stalks are sometimes made into ethanol.
The internet also tells me that it is believed that the crop was introduced into the Unites States by slaves who brought seeds with them from West Africa.