Wheatgrasses and wheat look-alikes are true spikes--they have no branches on the seedhead, just the seeds (spikelets)
directly attached to the main stem (rachis). Most grass seedheads do have branches. If so, it isn't a true spike and
therefore not in the wheat category. Fiddle with the seedhead to see if the spikelets ("seeds") are directly
attached to the axis. If they are, it is a true spike.
Here is a picture of commercial wheat with two seedheads having
alternating rows of spikelets on the rachis. Your wild wheat-like grasses won't have such large seeds. Other grasses in the
wheat-like category include rye and barley. All of these have true spikes and
most are awned.