The Quick Guide to Wild Edible Plants: Easy to Pick, Easy to Prepare

Deadly Harvest: Plants You Should Avoid

13 anyone who is a wild food forager needs to recognize the most seriously harmful plants they might encounter. Throughout much of the United States, this means Poison Ivy (Toxicodendron radicans) and its lesser-known evil cousins, Poison Oak (T. pubescens) and Poison Sumac (T. vernix); all of these cause dermatitis. We also include two of the most deadly plants to ingest, Poison Hemlock (Conium maculatum) and Water Hemlock (Cicuta maculata). poison ivy, poison oak, poison sumac the dermatitis-causing sumacs need to be carefully distinguished from the common red-fruited sumacs. Present-day botanical classification places the dermatitis-causing plants into the appropriately named genus Toxicodendron (“poison tree” in Latin) and the other sumacs, well known for their edible fruits, in the genus Rhus. As a result, older literature will, for example, refer to Poison Ivy as Rhus radicans and more recent writing will refer to Toxicodendron radicans. All parts of Poison Ivy, Poison Oak, and Poison Sumac cause dermatitis in any season and should be avoided. The chemical compound that causes the blistering and swelling is urushiol. Other plants in the same family as Poison Ivy, the Anacardiaceae, include Mangos, Pistachios, and Cashews, all of which contain small amounts of urushiol in their unripe fruits and vegetative parts. This explains why some people have food allergies to these well-known products. All three species of Toxicodendron have alternate compound leaves. The leaves of Poison Ivy and Poison Oak have three leaflets, and those of Poison Sumac have seven or nine leaflets. Poison Ivy is a woody vine with compound leaves up to 6 inches long. The stem of Poison Ivy is adapted for high climbing in trees and has specialized roots that attach to the bark. Deadly Harvest: Plants You Should Avoid the quick guide to wild edible plants 14 Flowers are green and inconspicuous; fruits are white berry-like structures that ripen in late summer. Where can you expect to find Poison Ivy? Just about anywhere you are looking for wild edibles. It has a remarkable breadth of habitats from ocean dunes to mountain forests, margins of marshes to urban settings. Unlike its very similar relative, Poison Oak is not as widespread nor as frequent as Poison Ivy and is often confused with it. It prefers drier habitats and is a small shrub that never climbs high on trees. What distinguishes Poison Oak is its overall hairiness and the distinctive lobing of the leaflets, which can bear an amazing resemblance to oak leaves. It is, however, no relation to true oaks (species of Quercus). Nor is it related to the common English Ivy (Hedera helix). Poison Ivy leaflets can also be lobed but never to the extent of Poison Oak. The leaves are the same size and the flowers and fruits are superficially similar. Poison Ivy in midsummer: Each leaf consists of three leaflets. The terminal leaflet is symmetrical, but the lateral leaflets are not—a good diagnostic feature of this dangerous plant. Developing fruits are seen at the middle right. 15 Deadly Harvest Last in the lineup of these villains is Poison Sumac. Fortunately, in most of its range through the eastern United States it is not very common nor does it form extensive stands—unlike its congeners—except in peat bogs in the upper Midwest. A shrub to 15 feet tall, it has the most specialized habitat preferring wetlands. And the leaves of Poison Sumac are much different than Poison Ivy and Poison Oak. Like its relatives the leaves are alternate in their arrangement on the stem but rather than three leaflets. Poison Sumac has 7–11, always an odd number with the leaflets (not the leaves) opposite one another on the leaf stalk. The leaf stalk is dark red, a consistent identification feature. Be on the alert for these wicked plants. Fascinating in their own way, they should nevertheless be avoided, since even brushing against them or being exposed to smoke when they are burning can cause dermatitis in sensitive people. You may encounter Poison Ivy almost anywhere; Poison Oak is less widespread, and Poison Sumac is seen very infrequently. Poison Ivy in late winter: The numerous hairs (aerial roots) growing off the thick, woody stem are a good way to recognize Poison Ivy in the winter. The winter buds are rusty brown (lower center). 16 Poison Oak: several of the leaflets resemble oak leaves...