Gonna be a tough one to visualize I know, but I'm trying to figure out where
my cat is picking up these things.

Anyway, he's coming in with these BB sized green seeds(??) stuck to his fur
that take quite a bit of effort to remove. They aren't sticky so much as I
think they're more like velcro, they stick to all the fabrics in the house
which makes it tough to get rid of them with a vacuum.

Any ideas what plant is producing those? All I can think of is perhaps the
climbing Wisteria I have on my fence, the grass/weeds in the back 40 or what
I don't know.