Young dogbane looks strikingly like young milkweed, but there are a few key differences to keep in mind. Dogbane does not have a hairy stem and when cut it has a solid center. Both dogbane and milkweed produce a milky sap when cut. The sap dogbane produces tastes absolutely terrible, while milkweed sap is rather neutral tasting. Later stages of these plants show many more differences. One of the reasons I am confident about this plant being dogbane is because this particular field is full of dogbane every year, but completely lacking in milkweed.