Bristly Foxtail

After recently receiving a copy of Grasses, An Identification Guide, written and illustrated by Lauren Brown, I thought I'd try my hand at a grass ID. Rather than following the key guide, I simply scanned the pages for the distinctive seed head. It took no time to identify today's species as a member of the Bristly Foxtail, Setaria, genus.

It's probably a bit late in the season to positively identify the species but my guess is that this grass is the Green Foxtail, S. viridis.