I pulled this plant out of my yard this morning with my bare hands and a sticky white substance came out and got on my hands. After only a few minutes, my hand starting feeling numb and now it is itchy. What is that substance and what is going on with my hand?
This is the sap from the plant, which is toxic if ingested and will cause contact dermatitis of the skin (reddening, itching, stinging) in sensitive people. Wash your hands thoroughly and it should eventually go away on its own. If not, seek professional help. In the future, you may want to wear gloves when handling these plants.