Pursuant to the discussion below, I took the 7d out to the front garden this evening to film the sweat bees at work:

As several of you pointed out, grasses are supposed to be wind-pollinated. But the bright colors of grama flowers surely can’t serve any wind-related function. I suspect the bees are giving the pollen an assist- not necessarily by carrying it among flowers but by helping launch the pollen on its way. The video shows pollen streaming into the air as bees land on the anthers.

What do you think?