There are a variety of tree-climbing vines in Eliza Howell Park and lately I have been examining the ways in which different species climb trees and shrubs. I am aware of four climbing methods used by different vines in the park.
Some vines have tendrils, thin leafless growths, often in spiral form, that stretch out and wind around a support. Greenbrier, the green stem in this picture, is one example.
Wild Grape, one of the most common vines in the park, also climbs by tendrils. Grape tendrils tend to be forked. Here, it looks llike two different Grape stems are reaching out to each other for support.
Thick Grape vines can often be seen hanging from large trees, unattached to the tree trunks (different from Poison Ivy, which also grows high but adheres to the trunk — see below). The large and heavy Grape vines are attched high in the tree. In this picture, the Grape vine is on the right.
A second method used by vines is twining, winding around a stem or limb or trunk like a rope. In Eliza Howell a good example of twining is Oriental Bittersweet.
Often several shoots of Oriental Bittersweet wind around the same tree or stem – and/or around one another.
3. Aerial roots.
Aerial roots are roots that grow from the plant above the earth surface. They are able to attach the vine to the surface of the tree trunk (or whatever surface it it climbing). In Poison Ivy, which clinbs with aerial roots, the effect is a hairy look.
Sometimes different vines grow on the same tree, providing a good opportunity to compare different climbing mechanisms. Here a Wild Grape is stretching its tendrils toward two large Poison Ivy vines. Note the hairy look of the Poison Ivy.
4. Adhesive disks.
Some vines climb trees by adhering to the trunks by using small adhesive disks. An example in the park is Virginia Creeper. Virginia Creeper grows right up the side of a tree, tight against it, as does Poison Ivy. but there are no “hairs,” no roots, visible. At first look, the vine’s support mechanism is not obvious.
Upon closer inspection, one can see the small tendrils that end in grasping disks. I have circled one side growth with adhesive disks that helps provide the support for this vine.
I usually identify the vines of Eliza Howell by their leaves and by their fruit (and sometimes by their bark). It is very helpful to have another method of identification in the leafless season, a season that is a great time to learn more about how the vines grow among the trees.