Poison Plants


Hello! I’m not sure if this is the right channel to direct this question, but I’m hoping that if it isn’t, you can point me the right way.
My wife and I recently returned from a trip to Rhodes and on our last day there, I developed a strong rash on both of my shins. It had been unusually hot, so I wasn’t sure if it was a heat rash or an infection or what else, but having hiked the day before in shorts (due to the hot weather) I realized the most likely culprit was an allergic reaction to a plant. I have a few photos of some plants/shrubs that I took on the hike, and was wondering if someone could help me identify them? It would be great to solve the mystery, if possible. Thanks either way.


Thank you for contacting the Toronto Master Gardeners.

In order to make a correct identification, we look to plant characteristics such as bloom time, growing requirements, overall height as well as physical characteristics such as the leaf’s shape, margin, how the leaf is positioned on the stem- alternate or opposite, as well as the flower arrangement, colour and shape. It is very difficult to tell all this from a photo that is taken at a distance. Also, the Mediterranean climates and mineral-rich soil of Rhodes encourages the growth of a variety of plants that we are not familiar with.

You may wish to compare your photographs with the pictures posted here of the common plants of Rhodes.

That being said, the plant on the right of your photograph appears to be a type of thistle which are very prevalent on Rhodes. This plant contains a milky sap which comes out of the leaves when broken which can cause a rash.

The photo on the left is quite blurry; however based on the leaf shape and leaf margin, my guess is that it is a type of stinging nettle. The stinging nettle is a plant found practically all over the world. The leaves and stems of the plant are covered with brittle, hollow, hair-like structures. The stinging hairs act a lot like a hypodermic needle when your skin brushes against them. Chemicals flow through the hollow tubes and cause a nasty stinging sensation and a rash. More information on this plant can be found here.

If the rash is still prevalent,  my advice would be to see your family doctor.