I’ve seen it in dove craws as long as I’ve killed them. I’ve made mention on dove hunts the birds are hitting the green patches in the corn. I’d always assumed that’s where they were getting those black seeds. Those pics look similar to wild mustard and or wooly croton. I’ve seen goosegrass seeds or something similar too. I have a hedge row of autumn olives and they hit those too when the berries are right

“Socialism only works in two places: Heaven where they don't need it and hell where they already have it.” ― Ronald Reagan