Poison hemlock, one of the most poisonous plants known to man, is now in its flowering period and has been slowly spreading throughout Ohio. This plant tends to grow alongside bike pathways, near park edges and fields, in ditches, meadows and dense colonies near the freeway. It is most common in central and western Ohio. According to the Cleveland Clinic, “Poison hemlock isn’t like poison ivy or poison oak. You usually won’t get a rash from touching it. Most of the time, hemlock is only poisonous if ingested. However, you should still be careful when handling poison hemlock.