It is easy to make rash judgments when the subject is poison sumac.
Poison sumac incites a reaction from most whenever it comes up in conversation. Eighteenth-century Swedish botanist and protégé of Linnaeus, Peter Kalm, observed, “I have known of old people who were more afraid of this tree than a viper, and I was acquainted with a person who, merely by the noxious exhalations of it, was swelled to such a degree that he was stiff as a log of wood, and could only be turned about in sheets.”
This reaction is not surprising, since poison sumac has been called the most toxic plant in the world. Though this plant has earned its reputation, more often than not, what folks have been afraid of is not necessarily the real McCoy.
Poison sumac is very often confused with other sumacs, including winged, dwarf and staghorn sumacs. The latter three are not toxic at all, and their berries are even edible. It is easy to tell these plants apart. I’ll bet that you are itching to know how.
Having “wet feet” is the only way to go for poison sumac. It is found exclusively in wet areas, bogs, swamps and along streams. The other sumacs prefer dry soils and are seen in fields, woodlands and along roadsides. The berries of poison sumac are white or gray, while the other sumac berries are brilliant red. Even the leaves are telltale: Poison sumac’s are smooth and the plant has no hair on its stems. Its flowers are yellow-green and insignificant, so if you notice them, you are likely too close to this powerful plant.
If you have a little time at your disposal, there is an ingenious way to confirm the identity of poison sumac, and also poison ivy and poison oak. Wrap the stem or leaves of the unknown plant in a white piece of paper (be sure not to touch it with your bare skin) and crush it. If a brown spot appears quickly and then turns black within a few hours, you have one of the terrible threes.
Do be irritated if you find poison sumac, as it can cause quite a reaction in most people. I say most, since about 15 per cent of the population is not allergic to urushiol, the compound in poison sumac (and poison ivy and poison oak) that causes the rash, blisters, and terrible itching associated with all three plants.
Urushiol is incredibly powerful and could take its place among the world’s top biological weapons, though I hope not to give anyone any ideas. It only takes one nanogram (one billionth of a gram) of urushiol to give a person a rash. The amount of urushiol on the head of a pin could irritate 500 people, and one quarter of an ounce is enough to make every person on earth itch! Even worse, urushiol remains active for up to five years.
It is difficult for people not to be inflammatory when speaking of poison sumac. Animals, on the other hand, would find our aversion peculiar, since they are not allergic to urushiol and aren’t affected as we are. Beware, though, since animals can carry the urushiol-containing oil and transfer the still virulent stuff to our skin and clothes. Some birds and mammals, including bobwhite, pheasant, grouse and rabbits, even eat the berries during the winter when food is scarce.
Never, ever taste this plant yourself. The notion that eating it will lessen an adverse reaction is completely false and a dangerous hypothesis to test. Remember this rhyme to identify the good sumac from the bad sumac: Berries of white: oh, what a fright; berries of red, yummy instead. Your skin and taste buds will both be glad you did!
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown