Like the majority of the cucrbits, the family Coccinia is dioecious. Here is a scholarly little blurb about them.

As for care, I'd treat it just like C. grandis, but that is only because I couldn't find any specific culture information about C. quinqueloba...

joscience,

Apparently the genus isn't entirely dioecious. In "The Illustrated Handbook of Succulent Plants" by Urs Eggli (google books pulls this up), he describes Coccinia sessilifolia as "Monoecious climbers with tuberous Rstock; stems to 5 m..." However, in the summary of Coccinia at the beginning, he says "Climbers or trailers, sometimes with tuberous R-stock, dioecious, tendrils simple or bifid near tip..."

Moreover, there's also this--a draft key to Cucurbitacae. The Coccinia section seems to be written by Lu Anmin and Charles Jeffrey: "Climbing herbs; roots tuberous. Branches glabrous or slightly scabrous. Tendrils simple, rarely 2-fid. Leaf blade angled or divided. Flowers dioecious or rarely monoecious. "

http://www.fna.org/china/mss/volume19/Cucurbitaceae-MO_coauthoringFeb2007.htm

So it appears that a small number of the genus are monoecious. Is C. quinqueloba among them? Without any specific knowledge of this species, I think you can see why I am confused. Joscience, can I assume that your knowledge came from general knowledge about the genus, and not about this particular species, which may or may not be an exception to the usual rule?

Yeah, you assumed correctly. I definately don't know from personal experience. As you've clearly shown, there is some contradicting information out there. Honestly, your references seem more authoritative, or at least more specific. Still, I tend to favor the most statistically likely outcome: that yours is dioecious.

Anyway, I guess that puts you back at square one until someone who actually grows these can tell you (or yours gets old enough to flower!).

I'm surprised the nursery didn't know. Where are they getting them from?

joscience,

They grow the plants from seed. Whether these come from their own plants or someone else's I don't know.

In terms of the nursery, while I was there I spoke to a woman who grew it at home. She said it fruited for her, but that the neighborhood kids stole most of them! It's a rather vigorous vine (she planted it in the ground) and I find it hard to imagine that she brought home 3 plants of a vigorous vine given all the other plants the nursery sells (roughly 1000 species/varieties--it's actually quite amazing). It's a big place (wholesale + retail) with about 30 employees, so that when I emailed them I got someone who was not as familiar as the plant. She answered several questions on it, but did not know the answer to this one and didn't seem to want to find it out. I suppose I could have insisted she track down someone who knows, but I figured I would let it go and find out through other channels. I might learn a bit about the plant in the process. And I assumed this would not be too difficult to find out.

However, your question of where they are getting them from made me think if there might be anyone out there who would sell them. The obvious place to check that I know of is Silverhill Seeds in S. Africa. I checked and they do in fact sell it. I have little doubt they will know.

Thanks!

Sorry to not follow up on this sooner.

Joscience--it seems you are right. I eventually wrote to Kirstenbosch Botanical Garden in S. Africa and a woman there confirmed it was dioecious. She said she would forward my email to a couple experts to be sure, but I didn't hear back. I never heard from Silverhill either.

That said, I'm curious about the growth habits of the plant, and I will post a separate thread.

I wouldn't say I was right, just lucky ;-) Anyway, all the glory goes to you for that impressive bit of sleuthing you did! Thanks for reporting back to the group.