I've had this plant for years and years, and know very little about plants but enough to know this one probably isn't North American native. Who knows. I've attached the pics; first is a full shot and the second a close-up of the leaf shape and veins. It's kind of a vine in that it tends to trail, but can grow upwards for a while until it gets too heavy to suppport the leaves, and then it will start to droop. It's the kind of plant that never ever flowers, and can have a vine cut off (with enough leaves still attached to feed it) and put in a new pot and it will start a new plant. The roots are very very tiny and stringy, kind of like tinsel. They look ridiculously wispy to support such a huge plant. It hates temps below 50-60 degrees F, and doesn't need water too often. When you break off a leaf, white thick and slightly sticky goo-foam comes out from the wound, and after that wound has healed, usually a new branch-vine will grow from it. The branch/vine part of it is very very smooth and a little shiny when it's in good health; when it's been damaged or left in the cold, the branch skin will turn paper-bag-brown and very rough, almost like the bark of a tree or some such. That's all I know about it. The person who gave it to me out in Oregon thought it was coca (as in the drug) but it's not (thank god), according to the Googling I've done on that plant. Anyone seen this before? I have never seen anything like it anywhere else. Thanks!
The photo of the leaf almost looks like some kind of euphorbia, and the fact that you say it leaks a milky substance when you break off a leaf leads me to believe that it may in fact be of this genus. Just a guess though, I am no expert just a plantluver.
Not so sure I would rule out coca so quickly. Likely not Erythroxylum coca, but the leaves do look possible for other Erythroxylum. Plants grown in low light often cannot support themselves and fall over appearing to vine. Take a look at the leaf here: http://herba.msu.ru/shipunov/else/images/erythrox.png
Erythroxylum does not have sticky white latex, as described by mysteryplantquestion. I still think it's Synadenium.
