Toxic Members of the Carrot Family By Susan Camp Giant hogweed, the subject of last week’s “Gardening Corner” is invasive and poisonous and has been discovered in Clarke County, but giant hogweed isn’t the only member of its family that has some nasty traits. Several other species of Apiaceae, also called Umbelliferae, might be growing on your property right now, and, if not, might be ones you encounter as you travel around the Commonwealth this summer. If I walk down our gravel road right now, I will see Queen Anne’s lace (Daucus carota) growing 1 to 2 feet tall along the roadside. Native to Europe and southwest Asia and naturalized to North America, Queen Anne’s lace, sometimes called wild carrot, has the delicate, finely cut green leaves, stiff, hairy stems, and dainty white flowers arranged in umbels that are characteristic of many members of the Apiaceae family. The root of the young plant is edible, but the leaves can cause photodermatitis or skin inflammation exacerbated by exposure to sunlight. I had a friend who once used the pretty flowers to decorate the tables for a wedding reception, but Queen Anne’s lace holds a dark secret: it resembles poison hemlock (Conium maculatum). Poison hemlock is taller, reaching 6 to 10 feet at maturity, with hairless, purple-streaked stems; erect, umbrella-shaped clusters of white flowers; and finely cut, ferny leaves. All parts of poison hemlock emit a foul odor and all parts are toxic to humans and animals. The plant contains the chemical compound coniine, which acts as a nerve agent that ultimately causes paralysis of the respiratory muscles. Poison hemlock is an invasive non-native that is found all over Virginia and the rest of the United States. Don’t even touch this plant. Water hemlock (Cicuta maculata) is another highly toxic member of the carrot family. It is a native that is found growing all over Virginia in marshes, wet meadows, streambeds, ponds, and swamps. All parts of water hemlock are poisonous, especially the roots. Ingestion will cause a variety of unpleasant symptoms, culminating in fatal grand mal seizures. Water hemlock reaches a height of 8 feet at maturity. The hollow stems are mottled with purple. The toothed, lance- shaped leaves are not characteristic of the carrot-like foliage of many Apiaceae members. The tiny, white flowers grow in umbels 2 to 6 inches across. Water hemlock smells like parsnips. It is considered one of the most poisonous plants in North America. Speaking of parsnips, cow parsnip (Heracleum maximum), a North American native, grows across the United States, except for the Gulf Coast and the very deep south. It reaches a height of 7 feet and has deeply lobed leaves and the characteristic white flowers in domes or flat-topped umbels. Like giant hogweed, cow parsnip contains furocoumarins, which cause blistering and discoloration of the skin after exposure to sunlight. Wild parsnip ((Pastinaca sativa) grows to 4 feet at maturity and has lobed leaves and umbels of yellow flowers. The woody stems are hollow and ribbed. The root of wild parsnip can be eaten, but the sap of the leaves and stems contains chemicals that cause a red, blistering, poison ivy-like rash after exposure to sunlight. Angelica (Angelica archangelica) looks very similar to the other members of the carrot family. Angelica grows to a height of 8 feet with finely toothed leaves and yellowish flowers. The thick, ribbed stems have a purple tinge. Angelica is cultivated for its edible stems, which are candied and used in desserts. Angelica contains furocoumarins, too. The fresh roots are poisonous. Most of these carrot/parsley family members are biennials that bloom during the summer months. All of them have some degree of toxicity. While they are attractive, they are best admired from a safe distance. And buy your carrots and parsnips at the supermarket. The Virginia Master Naturalist booklet “The Socrates Project: Poisonous Plants in Virginia” is an excellent resource with basic information, photographs, and links to websites with information on many poisonous plants. July 5, 2018 .