Only the first three are Poison Ivy. The last one is Hedera helix, Ivy, but there is a little PI on the right. The penultimate picture shows Nandina domestica. Ironically, only the PI is a non-invasive native plant.

While there are several name brands that have good poison Ivy killers, we have been using on from Ag Supply. It is called Tiger Brand® Brush Killer and contains Triclopy as the triethylamine salt - 8.8 % It is a concentrate, that is diluted and applied in a sprayer.

I have seen this brand in several farm supply stores like Tractor Supply. The reason I am mentioning it is that if takes several application to eradicate poison ivy as it is spread by birds and other seed eating animals. It is less expensive than the name brand products.