I received these pictures from Grad Student Andrew Hoiberg on March 23. They were taken in a very protected area by animal science on ISU campus. I did another check of the areas on campus where I see crabgrass first each year on the morning of March 24 and still see no crabgrass germinating in these areas. I'll keep you posted on other developments.
These are the real thing. It is large hairy crabgrass. Notice the pointed leaf tip and the fine hairs on the leaf margin.
I would like more pictures from around the state as you see crabgrass emerge. I will get them up on the blog. This does appear to be one of the earliest springs in my 33 years here in central Iowa.