No responses? I'll give it a stab, although I trust someone will correct any mistakes...

First off: as far as I know Passion flowers are bisexual or "perfect" flowers with both male and female parts. Particularly with hybrids though, you may run into plants that will not fruit or produce fertile pollen. However it sounds like we're only talking species here.

P. edulis f. edulis: purple passionfruit--is self fertile. P. edulis flavicarpa: yellow passionfruit--requires another clone.

Hybrids between yellow and purple P. edulis vary, some are refered to as "semi self-fertile" and benefit from having P.edulis f. edulis in the vicinity.

I take it "purple giant passion fruit" is just a large form of P. edulis f. edulis? I've heard such varieties exist.

P. alata: I found this on the Cloudforest Cafe. It's self-fertile, but that requires hand pollination.

P. quadrangularis. This is interesting. I found this from a book "Tropical Plant Breeding", Charrier, et al. (on Google Books). The form which produces lots of small fruits is self-fertile. The form which produces few very large fruits (P. quadrangularis var. macrocarpa) is self-sterile.

P. alata and P. quadrangularis are very closely related and I would assume that they are fully cross-fertile.

You mention "red passionflower" at the end. Is this P. vitifolia or P. coccinea/miniata (or a hybrid of the two)? If so, you do need a separate clone. P. caerulea may also work--I'm not sure, though.

A final question is whether you have the right bees. I mention this with respect to alata/quadrangularis. I don't know whether or not you do.

excellent, I will send you some seeds fro helping me of whatever kind you want. I just have some quick questions. what do you mean by having 2 clones to produce fruit. just 2 seperate plants of the same kind...and do they both have the same organs? Its not like a marijuana plant where it has to be a female and a male to produce seed is it? what do 2 seperate clones do to each other and what do i do with them so they produce fruit? also when you say erquiers hand pollination, I live in florida and the p. coccinea that I have outside , ants love it. there are 2 varieties of ants that you would swear live in the flowers....all day long each flower has like 8 ants crawilng in adn out to another...would this benefit me from hand pollinating.what is your opinion on crossing some of the varieties together?

Two clones means that they need to have originated from two separate seeds, and therefore they are genetically distinct. A lot of varieties are passed around for years by rooting cuttings. It might not even be obvious that two plants coming from different companies/nurseries are in fact the same clone--you have to be careful. For some species I understand there are actually a very small number of clones in general ciruculation. I think I heard this is the case for coccinea and vitifolia, for example. Each passion flower has both male and female organs, so that's not a concern, although there may be instances of clones that do not produce viable pollen or fruit. This is common for hybrids--I'm not sure about species.

As far as how this works, I don't know the details, but i assume it is somewhat analogous to an immunological response in animals, whereby self vs. non-self is recognized. If the pollen is from the same clone, the plant must have mechanisms that recognize this and prevent pollination. I don't know offhand what those are.

So if you need two to make fruit, once you have the appropriate plants, you need to have the correct pollinator, which can be a bee, bird, bat, etc. To be honest, I don't have a clue how this works for each individual species--perhaps someone here knows for the ones you mention. I do seem to recall that for the bee pollinated ones, often the bigger the bee the better (e.g. Carpenter bees)--they are more likely to brush up against the reproductive organs.

Sometimes the situation can be very specific. For example, the rare and possibly extinct P. parritae is thought to have gone through a big drop in population when its only pollinator (a hummingbird) moved to higher altitude due to the effect of global warming.

In California we have non-native Argentine ants. They are also extremely common. I've been told that some of the Tacsonias in Strybing Arboretum in San Francisco are pollinated by ants as you suggest (their normal pollinators are generally humingbirds, I think larger than our species).

If you need to cross pollinate to get fruit, there should be no difference (perhaps tiny?) no matter the source of the pollen. Of course if you want to grow new plants from seed, this does become important. I believe P. coccinea (miniata) x vitifolia and P. quadrangularis x alata hybrids are very common.

so, I could pollinate one of the self steril with another passion flower fruit plant that is not the same. Like can I make a self steril P. quadrangularis produce fruit by hand pollinating it with pollen from another fruit producing variety such as p. alata or P. edulis? it dosent require 2 diffrent identical plant species dose it like 2 P. quadrangularis crossing pollen between plants? very good explination on fruiting tho.

You can often cross pollinate with pollen from SOME different species, but not all. It might be trial and error, but for example in subgenus passiflora, P. caerulea works well in a lot of cases. Your chances in general go up if the species are closely related, providing they have things like the same number of chromosomes (we should all be grateful that chimps and humans differ here, by the way...). So it's not surprising that pairs like P. coccinea/vitifolia and P. quadrangularis/alata can pollinate one another.

Of course people have made hybrids of many species. You can look up the parentage of these. Myles Irvine's site has links to lists of these hybrids. However...all it takes is for one cross to work extremely rarely and give only one seed. What you want, of course, is to reproduciby get fruits full of seeds.

I don't know offhand whether P. edulis and P. quadrangularis can cross pollinate. Again, you can look up the hybrid tables but you don't want a rare event. Maybe someone reading this would know.

good explanation. I will try to see if I can find the tables to look them up.

I am only familiar with Incarnata. Since it has both male and female organs in a single flower(like tomato), therefore it should self polinate. Breez, insects,.. can also help to assure it.
But in my area there are a lot of bumble bees and they just love the Incarnatta flowers. This year I will protect one from bees to see if it will self polinates. My guess is that it will.

I just checked this--for two threads--and found an abstract from a paper about P. incarnata pollination:

Passiflora incarnata (Passifloraceae): A new fruit crop

Author(s): McGuire CM
Source: ECONOMIC BOTANY Volume: 53 Issue: 2 Pages: 161-176 Published: APR-JUN 1999
Times Cited: 6 References: 138

Abstract: Passiflora incarnata bears flavorful fruits consumed by past and present peoples, and this plant deserves greater use as a fruit crop. Native to southeastern North America, it is an herbaceous perennial vine which flowers and fruits over much of the growing season. P. incarnata is self-incompatible and usually pollinated by carpenter bees (Xylocopa spp.). Plants are functionally andromonoecious, and low resource status favors male flower production and thus reduces fruit set. The fruits contain many seeds, each surrounded by art aril holding edible juice, and this juice can be consumed fresh or used in processed products. Because it is a minor agricultural weed, P incarnata should not be introduced into regions where it may naturalize. Polyploid hybrids of P. incarnata and the subtropical and tropical passionfruit, P. edulis, are also potential temperate fruit crops. Future research on P. incarnata should evaluate intraspecific genetic variation and performance in cultivation.