Hedge Apples come from the Osage Orange Tree (Maclura pomifera) not native to the Maryland area. It can grown around 35 feet or more, is a hard wood, leaves turn yellow in the fall and they produce this greenish 3 - 5 inch fruit that drops to the ground at this time of year. As they break off the stem produces a milky sap. It can irritate the skin of some sensitive people. There is a folk lore that says it makes a good bug killer - wonder if it will work on stink bugs? But, there is no proof as of yet research is being done on this interesting little fruit. So, who knows, can't hurt to have them around, just in case.
If nothing else they are a nice compliment to my orange pumpkin. Happy Fall!