I too am EXTREMELY SENSITIVE to poison ivy and recently broke out in a similar rash after being careless while propagating my all time favorite plant, the philodendron micans. I also suspected that had to be it so I took a fresh cutting and dabbed the sap several times in my arm and didn't wash off for a few hours. Somewhere between 12 & 24 hours later, I started feeling that familiar itch and watched as my test patch gradually spread out the size of a dime and rose up with the little tiny bubble pattern I'm used to seeing with poison ivy rash. THIS SUCKS! I'm in the middle of battling it right now and in my research found this helpful article. I also read another helpful tip that said the sap from these plants can somehow penetrate through standard medical gloves so thicker gardening type gloves should be used when propagating and caution should also be taken when refreshing propagation water. I plant to purchase some thick, SOLID rubber gloves that can easily be thoroughly washed. NOT those gardening gloves that have a breathable section at the back of the hand and wrists! You should also clean the tools you use and the work area. Rubbing alcohol AT LEAST 70% grade is known to be effective for cleaning tools that have come in contact with poison ivy so I plan on implementing that. As well as never shortcutting again by taking rushed cuttings and not doing the basics like laying out a protective mat and immediately washing my hands afterwards. I lazily let my NUMEROUS cuttings drop to the floor (CARPET!) and I know I didn't wash my hands right away like I normally do. A couple hours later I laid on this floor in a tank top and got a mild rash a day later across my upper back and shoulder area as well as my ear lobes which I believe is from handling my earbuds right after propagating my favorite plant. PLEASE MAKE MY PAIN WORTH IT AND LET THIS BE A LESSON TO YOU... PUH-LEAZE!

Looks like Fraser photinia except new leaves coming out apple green wouldn't be usual for that. But maybe seedling variants with new growth being colored like this at this stage of development are possible, with at least some red or bronze tinting coming later. Photinia serrulata is a synonym of P. serratifolia.

Yup, that would be it! (There's something ironic about dogbane growing all over a hill where people regularly walk their dogs..)

Yes, it looks to be perhaps Strophostyles helvola.