Our National Park Service reports that a group of mountain lion kittens have been found in a patch of poison oak. Poison oak has no

This is a useful photo because it shows how poison ivy, as a ground vine, becomes a climbing vine as soon as it finds anything

Here it comes again! Here in New England, everywhere you look, little red leaves of three are sprouting.  In the southern states it is probably

How did I know, immediately, without getting closer that there was no poison ivy in these weeds? Does that stone-brick decayed looking old-world wall suggest

You can find these two growing side by side; the lovely and evocative Jack-in-the-Pulpit, and the evil poison ivy. Both follow the leaves-of-three way of

Over the years people who are suffering from nasty poison ivy (or oak or sumac) skin rashes have sent in photos to share. They send

Blackberry leaves  do have a similar overall shape to poison ivy leaves, and leaves-of-three, and both grow as ground vines. But… blackberry has thorns, all

This is one of the most difficult plants to tell apart from poison ivy because they are both vines with leaves of three. In this

As spring rolls from south to north, expect to see lots of these two vines coming to life. One of them is our old buddy,

Here is a common sight in poison ivy country, which is much of the United States, east of the Rocky Mountains. Poison ivy loves to

While searching for poison ivy books at Alibris, my favorite online bookshop, I came across this terrific book by Cynthia Riggs, who has written a

I was able to find poison sumac (on Martha’s Vineyard) in the winter, but only because I used the iNaturalist app to see if it

Here is a small poison ivy shrub that is mostly covered by snow. In a situation like this, it is VERY hard to spot that

Poison ivy is an early and enthusiastic participant in the annual fall color party. Here it is on a suburban fence. I was so impressed

This was taken in lovely Duchess County in New York State on a particularly lovely dairy farm.  What happens in cases like this, where poison

In her own words: “My temples were swollen so badly that I saw one of the doctors jump in surprise when they came into the

As we all observe, poison ivy LOVES to grow on roadsides. It gets lots of sun, not much competition, and birds love to sit on

Hopefully you have heard the warnings to never burn poison ivy. If not, this is what can happen. This young lady burned some weeds, not

This is a positive test for poison sumac! Poison sumac is pretty rare and only grows in very wet areas, whereas poison ivy is everywhere

This large tree fell across a trail and was chain sawed off by a helpful person. But I wonder if they knew that the thick

This is a case where a picture is not worth a thousands words. You need to hear Maria’s story before you can appreciate just how

Poison oak is found in much of California. It is very adaptable to the dry conditions and it leaves change in shape and size depending

We are always surprised by how many visitors to our website are looking for information about poison sumac, not poison ivy and oak. It turns

This is a very common scene in the eastern half of the United States: roadside trees with poison ivy vines climbing up. Poison ivy grows

It has been an absolute rule: “Leaves of three, let them be.” If a plant has more than three leaves (or leaflets) in a group,