Monday, December 31, 2012

Friend or Foe?

(click to see a larger image of any of the photos)
Just because winter has chased the leaves from the forest's trees and vines, doesn't mean that you can't still get poison ivy. The worst case of poison ivy I ever got was in the winter time when I was helping my dad cut and stack firewood. After that I learned to ID the dreaded PI in ALL seasons and all its many guises.

What makes it more complicated to those that don't know how to winter ID poison ivy is that we have three very common vines that grow in our area and may grow all together as the photo to the right indicates. The three vines are: poison ivy (Toxicodendron radicans), virginia creeper (Parthenocissus quinquefolia), and grape (Vitis spp.).

Poison Ivy


Poison Ivy climbing on a tree trunk
Poison ivy is the chameleon. It can appear as a vine, ground cover, and even rather bush-like plant. It is an attractive and robust plant all year long. If it didn't cause extreme contact dermatitis as it does, I'm sure it would be a much loved garden addition with hundreds of cultivars.

In winter it is the large bush-like and vine forms that we see most while out on the trails and the dried - yet still very irritating to the skin - vines on firewood. Yes, you can get the poison ivy rash from the vines on firewood too. Vines on firewood will look much like the picture to the right. Older vines will be thicker, woodier looking with a lot more of the hair-like tendrils along the length of the vine - more like the first picture above.

See the detail below for a close up of the hair-like tendrils. The detail also shows a shoot where leaves will sprout from come the spring. Slender buds can be seen on the tips of the vines. The picture farther below shows a vine with buds growing along an old fence.

Tendril detail
Like the grape and virginia creeper, poison ivy also has berries and the remnants can often be spied on the winter vines. These often still have a light color that hint at the white color the berries originally were. Both grape and virginia creeper have dark fruits. Poison ivy produces tiny fruits in greater numbers than either of the other two vines. (Click on any of the images for a larger view.)

Identification?

Wikipedia has a list of identification aids for this tricky plant. You can find it here.

There is also a whole site on poison ivy here with more info and images which you can find here.



Poison ivy vines and berries. Notice bud at end of vine.
Of course the image search at google will show you many images as well. If you add other qualifiers to the search like "vine," you will get other results that will show you many images of that specifically like so. Try other qualifiers like "buds" and "berries" for other images.

Got a photo of a plant you are questioning the ID of? Try GardenWeb's Name That Plant forum for identification help.


Virginia Creeper

Virginia creeper's small looping tendrils and knobbed joints 
Virginia Creeper is another common vine in the Northeastern US. Some people are sensitive to this plant as well and may also get contact dermatitis but that sensitivity is no where near as common. I personally pull this from the gardens (in which it can be quite a "thug") bare-handed with no ill-effects.

It too has its beauty - attractive leaves with 5 leaflets, scarlet fall color, and blue-black berries. This is also a "robust" and vital vine that is not easily removed from the garden. And a word of warning - never rototill the roots of this plant. Each piece will sprout a new plant. Yes, personal experience talking here!

The thin-barked and green fleshed vine
Unlike poison ivy, you rarely see any other form of this plant other than a vine. You may occasionally, however, see virginia creeper appearing as a ground cover in the full-shade of the forest understory. It is only waiting for some sunlight before vining off to the nearest tree. I have read that ginseng, too often harvested completely from areas, can hide amongst these young, low-growing creeper plants for it too has 5 leaflets. A thank you to the creeper for hiding the besieged 'sang!

Virginia creeper vines have a very thin bark with green flesh right under the surface. The vines have knobs or "knuckles" where the leaves would sprout come spring.
The tendrils grasping bamboo

The tendrils on the virginia creeper are never hairy. The tendrils are always small tight loops which they use to grasp fences, trees, or as in the pictures here, bamboo. All the vines featured here are very effective climbers.

Virginia creeper also has berries in the fall, but I have never seen them hold these berries into the winter season. The fruits are produced in clusters that have more of an umbrella-like arrangement than the standard downward hanging clusters that grapes prefer.

Identification?

Like with many plants, google image searches provide many wonder photos to compare against and learn from. Find one such google search here. Add other qualifiers to see more.

For information as well as images, please see here or here.


Grape
The large looping tendrils of the grape

Last but definitely not least, is the wild grape. The grape is the only one of the three vines featured here that is not poisonous - in fact, the fruit is edible and foragers can collect them for preserves and food. The leaves and young shoots are edible as well. Stuffed grape leaves - who doesn't love those!

The wild grape in our Northeastern forests can grow into such large woody vines that not only Tarzan but Tantor his elephant could successfully swing on them. The vines are also so plentiful in Eastern North America that the Vikings who discovered America, named the continent "Vinland" - "vine land." (The Vikings were first Europeans to discover America - sorry, Christopher Columbus!)

The bark and filaments in a grape vine
The grape is the visually most woody looking of the three vines. It has a rough bark when the vines get any sort of maturity on them. Larger, mature vines have almost a shaggy appearance to them with paper-like bark bits hanging from the vines. Even young vines demonstrate that papery quality if you break the vine - as in the picture to the right. Woody filaments are visible right under the surface of the bark and undoubtably give the grape vine some of its toughness and strength.

Last season's grapes
The grape also has rather knobby joints and "knuckles" on the vine - as you can see in the pictures here. But the large looping tendrils will not be confused with either of the two other vines featured here. See the picture at the top for a size comparison of of the tendril loops of the virginia creeper and grape. Side-by-side, the difference is incredibly obvious.

The grape often holds its last season's fruit clusters and maybe dried out bits of fruit on its vines. Albeit smaller, the wild grape fruit clusters look just like the cultivated grape clusters bought in a grocery store. They will look like a grape cluster to you.

Important - Before eating any wild grapes, be sure to know how to ID them from the poisonous look-a-like Canada Moonseed (Menispermum canadense). Always be smart and be safe.

Identification?

You have to love the images available via google - they are a boon to plant lovers and enthusiasts every where. Check out some wild grape images here and here. Use other qualifiers to the search for other image results.

Get more info and pictures of the wild grape from here and here.