apart from the fact that they all come from different plants, taste totally different, have different cooking properties, contain different amounts of gluten and grow in different climates, no not a lot.
Wheat, Barley, Maize, RICE
Wheat has a more broader and "coarser" seed head than barley, and the tufts/bristles (called awns) are shorter in wheat than barley. Corn or Maize is a much larger cereal grass, with the seeds on a cob enclosed by a sheath. The awns are very floppy and finer than either wheat or corn. Corn can grow up to 10 feet in height whereas barley and wheat only grow up to 4 feet in height. As far as deciphering individual grains, wheat is darker in colouration than barley. Corn is much different shaped than wheat or barley, having a rounded head as opposed to the sharp oval/diamond shape that wheat and barley have.
Corn (maize), wheat, barley, and rice are a few.
Rice, Wheat, Maize, Barley
Maize/corn, wheat, rice, barley, potatoes...
wheat, barley, sunflower, maize etc etc
The ingredients of Stella Artois are Water, Malted Barley, Maize, Hops. (no wheat)
Alfalfa, grasses, grains (wheat, barley, maize).
Wheat,Maize,Rice,Barley
rice, wheat, maize, barley and bajra(millet).
maize, barley, wheat, oats, sugarcane
rice, wheat, maize, barley and bajra(millet).