HAVE: Caudiciform cucurbit cuttings--Coccinia quinqueloba
I have a Coccinia quinqueloba plant that I've clocked at an average of 3 inches a day on 5 vines, and these were not the only vines growing. Hence I've had to take a number of cuttings to keep it under control--I have dozens.
The rooted cuttings are free, although if you have anything you think I might like, by all means let me know.
There is very little info about the plant online. If you locate an unusual picture of the fruit, it's not genuine--ask me for details. Since there is so little info out there, here are some pictures.
I bought the plant as a seedling in a 4 inch pot in mid-July. Here's what it looks like now in what's probably about a 2 gallon hanging pot. The vines have been clipped 4 times, otherwise they would be much, much longer. The earlier leaves are not deeply lobed; the later ones are.
The big question with caudiciform/tuberous plants is whether the cuttings will grow normal tubers; most will not. Here are three cuttings about 6 weeks or so old that I just dug up. They appear to show signs of tuber formation, even though the cuttings have not shown much vegetative growth yet. I take it as a very encouraging sign to see what appears to be the initiation of tubers so early on:
The tuber on the mother plant appears to be huge relative to the age of the plant--in one direction it extends 4 1/4 inches from the central stem. I have not dug it up so I don't know its full size. It also now protrudes above the surface of the soil by about an inch:
The plant also has interesting leaves:
And flowers (the species is dioecious, this is a male):
So although I can't guarantee these will reproduce the large tubers, there's certainly a chance and it would make a good candidate to raise the tuber to display as a caudiciform--although the mother plant seems to want to raise the tuber by itself...
I don't know what the hardiness is--probably zone 9 or 10. I don't know if it's deciduous--the mother plant is currently sending out a bunch of new shoots so I doubt that it will lose its leaves anytime too soon.
As I say, there is little info out there on these guys. One resource would be Birhmann's site--he has pictures of other Coccinias as well as short descriptions.