Alternating Leaves!

poison ivy leaves alternating

A viewer sent in this photo of a poison ivy (or possibly poison oak) vine.

What is striking about this image is how the leaves of three come off the main stem clearly alternating left and right. You rarely get such a clear view of how this works since the leaves usually hide the stems.

While the side leaflets of the compound "leaf of three" are right across from each other, the entire "leaf of three" is never right across from another "leaf of three". Other plants, such as box elder, often look like poison ivy, but their leaves do come off the main stem right across from each other.