23 July 2009

3 ivies together: poison ivy, Virginia creeper, English ivy

This is the continuation of an earlier post about a poison ivy plant I photographed at the Georgetown University Hospital last week. I took this picture in Rock Creek Park not too far from the hospital on the same day.


On the left is a poison ivy (Toxicodendron radicans) with its characteristics 3 leaves, in the center and to the right is a Virginia creeper (Parthenocissus quinquefolia) with its characteristics 5-leaflet leaves and covering the ground is the English ivy (Hedera helix).

Both the poison ivy and the Virginia creeper are native to eastern North America, but the English ivy is a native of Europe that is now naturalized in many parts of the U.S. It is considered an invasive plant.

As my friend Susan pointed out in her comment to the previous post, the young shoots of the Virginia creeper may have leaves 3 with leaflets, but there are likely to be some leaves with the usual 5 leaflets on the same plant, making the identification easy. The poison ivy, on the other hand, always has 3 leaves. The picture below shows a young Virginia creeper. Notice the leaf with 3 leaflets next to my thumb as well as the 4 and 5 leaflet varieties. As the plant grows, all the leaves acquire the normal 5-leaflet configuration.


Note added later: A few minutes after I posted this post I noticed that the 2 largest leaves of the Virginia creeper in the 1st picture actually have 6 leaflets each.


John said...

Nice illustration of the difference among the three. I have noticed that some Virginia creeper vines can take on a bit of a sheen as they mature, so the shape is very important for correct ID.

beejah said...

i am on the warpath against Virginia Creeper in my yard - it's pretty, but i'm very allergic to it. i'm in awe of the photo in this site of the man's hand deep in the stuff. a very ancient oak in my yard has thick creeper trunks running up it attached by thousands of tiny "roots." It has a Very Admirable life force.

Bassball_Batman said...

I've got Virginia Creeper up to 7 leaflets in my front yard. By the way, I've also seen 5-leaflets not bunched up together in Virginia creeper's signature starfish pattern. Instead, the "arm-and-leg leaflets" were spaced away from the head leaflet, trademark of poison ivy/oak. I didn't touch it to find out, but I'd be surprised if it were another type of Creeper.