You may know the saying "leaves of three let it be" or some
other passed down description of poison plants, but poison ivy, oak
and sumac can be hard to identify. All three plants contain the
same allergen causing the same reaction to your skin so your doctor
may call out any of the plants when identifying your rash.
Learning what the plants look like and where they grow can
help identify if it is poison ivy, oak or sumac.
Where does poison ivy grow?
The most widespread of the three, poison ivy is found throughout
most of North America, including all of the United States with the
exception of California, Alaska, and Hawaii. Poison ivy can grow in
many forms including a groundcover, shrub or a climbing vine.
Poison ivy prefers "disturbed ground" so you can find it growing
along the edge of your backyard, along paths, up trees and fences,
and mixed in with your landscaping.
The best way to identify poison ivy is by its almond shaped
leaflets of three - each stem ends with three leaves. The color of
the leaves can change from green to red with the seasons, and it
can contain berries of a grayish-white color (but not always).
Where does poison oak grow?
Poison oak is not as widespread as poison ivy, but to make
things more interesting there are two species found in the United
States, Eastern Poison Oak and Western Poison Oak. Don't let the
terms confuse you though, the plants look the same. Poison oak has
three leaflets like poison ivy, but they are scalloped and shaped
like the leaves from an oak tree.
Like poison ivy, poison oak likes "disturbed ground" but is also
commonly found in oak woodlands and Douglas fir forests. Poison oak
can grow as a shrub in the sunlight or a climbing vine in areas
that are shaded with colors ranging from bronze, bright green,
yellow-green or red as the seasons change. Poison oak may also
contain greenish-white or tan berries.
Where does poison sumac grow?
Unless you live in the swamp, it is very unlikely you will ever
cross poison sumac in your yard. Found in the Eastern United
States, poison sumac grows as a wooded shrub that may look like a
small tree (grows up to 20 ft.) located in very wet areas like
swamps and peat bogs.
The number of leaflets found on poison sumac are always an odd
number, typically ranging from 5-13 leaflets per stem, with a
single leaf at the end of the stem. Poison sumac stems are red in
the spring and become brown as the seasons change. Poison sumac
also produces clusters of small berries that are not perfectly
round (more oval in shape) and white or grey in color.
What is causing my rash in Hawaii?
Although poison ivy, oak and sumac do not exist in Hawaii, the
skin of the mango tree produces the same rash causing allergen,
urushiol. Just like with poison ivy, oak or sumac, you want to
remove this rash-causing oil from your skin if you have been in
contact with it.