Use caution with poison hemlock, ivy and oak By Trisha Gedon STILLWATER, Okla. – Flowers are blooming and vegetables are ripe for picking out of the garden, but unfortunately, poison hemlock and other toxic plants are also blooming across the state. Poison hemlock is one of the most toxic plants found in Oklahoma, excluding the Panhandle, said Laura Goodman, Oklahoma State University Extension range specialist. “Poison hemlock is toxic to many different livestock species. In fact, some…