Invasive Plants

Palmer amaranth, Amaranthus palmeri, is a new invasive weed in the pigweed family that has become a major challenge for farmers across the U.S. for much of the last decade. Native to the Sonora Desert of Arizona and Northern Mexico, Palmer amaranth is well adapted to the hot Maryland summers. It was first discovered in Maryland during the mid-twentieth century, but the presence of herbicide resistant Palmer amaranth was not confirmed until 2014. Since then it has spread to most regions of the state including Eastern, Southern, and Western Maryland. The spread of Palmer amaranth has been hastened by the movement of contaminated equipment, feed, and seed from infested areas.

Poison hemlock (Conium maculatum) is one of the most poisonous species among the higher plants. This plant contains poisonous alkaloids throughout all of its plant parts (vegetative, flowers, and fruits). Poison hemlock is acutely toxic to people and animals. If ingested, symptoms with appear 20 minutes to three hours after ingestion. Author: Doris Behnke; Title: Poison Hemlock (Conium maculatum)