Went for a hike today

We met a village couple at Kate Hill's house last week - Rene and Alvin from Liberty St. In Noe Valley.They  come for 5-6 months every year to stay in their house across the street from the village school. Rene is a walker and she took us for a sweaty hike. It rained last night and made the paths pretty soft - and this part of France has really clay mud

I  got a good stick to clear out the worst of it and we wiped them off on lots of grass. 

Now we need some help from you agriculture specialists. What is this plant? We have seen fields of it, not just an isolated bush somewhere. 

It's wheat harvest time and the trucks are bringing in the loads to the silos next to the canals and the harvesters are working as soon as the crops dry out. And when those harvesters start moving, they need lead vehicles to guide them and clear the road in front. we drive on 1.5 wide roads and when a harvester shows up on the radar screen, everybody goes into the ditch or driveway