Warning!!! Do not touch this plant! Giant hogweed poses a serious human health hazard because it exudes a clear watery sap containing photosensitizing agents. Skin contact with the sap, combined with exposure to sunlight, can cause severe burns and blistering.
Giant hogweed is a large perennial herb in the carrot and parsnip family, typically six to nine feet (occasionally to 15 feet!) tall. Giant hogweed also poses ecological impacts by forming tall, dense, and deeply shaded stands that inhibit growth of native species. Soil surfaces under giant hogweed stands become bare and more readily erode in the winter months.
Species that may be mistaken for giant hogweed include cow parsnip (Heracleum maximum), angelica (Angelica venenosa), poison hemlock (Conium maculatum), and common elderberry (Sambucus canadensis).