2. Black-eyed Susan
3. Rose of Sharon, Althea
6. Grape Hyacinth
7. Tiger Lily
10. English Ivy
12. Poison Ivy
Okay, I've never been good at identifying because I'm not someone who reacts to it. At least, so far I haven't reacted -- I've heard that you can build up intolerance over time. So when we were tromping around in that scrubby little section of our yard trying to fix the sprinkler, I kept thinking, "I'm pretty sure that's poison ivy, and I should probably do something about that." But I had to go look up whether the central leaflet of of the three has a long petiole, because I remembered that as one of the identifying characteristics.
So I'm pretty sure this is poison ivy:
And I should probably do something about it. I have friends who are highly allergic, and would cringe at the thought of our cats wandering around in this stuff and then rubbing against their legs.
Of course, you've gotta wonder what positive use poison ivy has. I've read that cows and goats eat poison ivy without issue, and that if you then consume the raw milk your sensitivity to the urushiol (that's the oil that causes the problems) will diminish. And I used Rhus tox as a homeopathic remedy when Thalia had chicken pox (it worked great, by the way).
Steve Brill mentions here that its roots provide erosion control, and it provides cover for small animals.
However, none of these things need to happen in my yard -- I'm not keeping cows or goats, I'm not making any homeopathic remedies (too lazy to do all that shaking), and small animals seem to have plenty of cover in the other weeds. So, theoretically, this plant will be killed now that it has been identified.