Also this are the things growing in my backyard (image taken from google).
Can I give my bunnies these? I'm pretty sure these are the things hay is made of.
The links have the words "bothriochloa laguroides" in them, which (I'm googling here) is silver beardgrass that also grows throughout the southern US. It might also be called splitbeard bluestem. Nothing shows up for "can rabbits eat splitbeard bluestem," but one USDA site has an article on it stating:
"Wildlife: Splitbeard bluestem benefits wildlife. Several species of birds and mammals eat the seeds and use the plants for cover. The white-tailed deer and rabbits also browse the plant."
That's about all I can find. If pet rabbits eat it, google doesn't seem to be aware of it.