My parents have had a strange vine growing in their yard since shortly after hurricane katrina. I noticed it last August when the bulk of the plant was about 10' long with around 20 runners shooting out up to 25'. The runners were round, but the stem on the main plant was flat and broad. I don't know if it had any fruit or flowers, but I'll try to find out. In the past year it has taken over most of their back yard. My mom said it grows as fast as kudzu. The soil is mostly sand, but sediment from the gulf washed on shore during the storm, so its much richer than it has been in my lifetime. The area had 10' of water and several houses were destroyed, so it could have been in someone's fridge or pantry.
First of all (and I may be wrong...), it seems to me that this plant is suffering from some fasciation - hence the flattened stem. Other stems in one of the photographs look normal in size to me (and with fewer leaves). Unfortunately, genetic or physical oddities, if that is what this is, aren't great for helping to ID a plant. Would you be able to get similar photographs of the long, skinnier vines - I'm particularly interested in whether the leaves are alternately arranged or opposite to one another, as well as whether the vine has [WIKI]tendril[/WIKI]s or not.
Yes: flattened part obviously fasciated. Look at the normal growths to figure out what it is. Looks familiar, but I can't name it.
I'm extermely sensitive to poison ivy ( I get it about 4 times a year) and I didn't have any reaction to this plant.
