Tag: urushiol

Is that poison ivy?

Is that poison ivy?

Yes, the above picture is definitely of poison ivy. In this late spring/early summer season, the question “is that poison ivy?” comes up really often on-line and in real conversations with actual people. The slogan “leaves of three, let them be” is a little too general to be helpful and even then people still seem to be confused and hesitant.

The pictures here are of real poison ivy taken in June in southern Connecticut.

Note carefully from the photo– poison ivy has three leaves: the center one is symmetrical and the outer two are asymmetrical, with jagged edges along the outside. Just as important, the stems of the outer two leaves do not run through the center of the leaf, but are located closer to the inner side of the leaf. This is a distinguishing feature you can look for when you can’t decide whether or not you are looking at poison ivy.

Younger leaves may be reddish and shiny, but more mature leaves are just green. And the amount of the irritant urushiol is the same on plants of any age.

creeper-2

Now let’s look at the above picture of Virginia creeper, a 5-leaved plant that doesn’t look anything like poison ivy. The problem is that Virginia creeper frequently grows right alongside or among poison ivy plants, and though it is not an irritant itself, you can regard it as a warning that poison ivy may be nearby. You can see that in the next two photos.

You will also see poison ivy climbing trees. What you may not see at first is the huge hairy rope-like stem the leaves grow from. The whole root also contains the same urushiol oil and if you grab that rope to steady yourself while gardening, you need to go wash your hands and arms right away. Even in the winter, these “ropes” still can spread the urushiol irritant.

Jewel weed

impatiens_capensis_photo2_lgIf you have jewel weed (a wild impatiens variety) growing wild nearby, many people report that the juice from the stem will help remove the urushiol and reduce skin inflammation. This was supposedly a Native American remedy and has at least some utility if you can get to hot soapy water right away. However, it does not seem to have been studied. If you develop a rash, lotions like Calamine will help reduce the itching.

In your garden

Poison ivy has the annoying habit of showing up in your gardens from time to time.

in pachysandra

This happens more every year as the carbon dioxide level in the atmosphere increases, and poison ivy loves it. You could put on heavy gloves and a heavy shirt and pull out the plants, but this usually leaves some roots behind which will eventually regrow. You can definitely kill poison ivy with Roundup, but in the garden it might kill valuable plants as well. A better choice is one of the commercial poison ivy killers: they all seem to contain triclopyr. This will kill broad leaved woody plants like poison ivy but leave grasses and the like alone.

Be careful in handling poison ivy debris: it all contains urushiol. Put the waste in a trash bag, never in the compost pile. And never burn it, since the smoke itself could still contain urushiol

Poison Oak and Poison Sumac

There are two other plants that secrete urushiol: poison oak and poison sumac. Poison oak has groups of 3 leaves that look rather oak like. Poison sumac is best recognized by the bright red stems. The Eastern variety has a rather short habit, while on the west coast, the bushes grow much taller. WebMD has very good pictures of all three plants. You will usually find poison sumac in or adjacent to swaps and wetlands, so unless you trudge through swamps you are less likely to see it.

Pacific poison oak is found mostly along the U.S. west coast, and eastern poison oak is mostly found in the southern U.S. It is somewhat similar to poison ivy and sometimes mistaken for it.

Advertisement