60% or more germination is a great rate for p. incarnata! I've planted seeds before without stratification, and only about ?10% of mine came up.
Moist sand in the fridge, I'll remember that!
Sherry

I think that 60 percent is on the low end. I took them back out last night to put some in starter pots, and I was hard-pressed to find many that weren't splitting with root tips coming out. Fortunately, I was looking for those already germinating, so I was in good shape.

Hi Jblaschke
Certainly works for incarnata (and probably lutea) - I have had then germinate within four days after being stored over winter in the fridge. Some tropical species will give high germination rates from fresh fruit but once dried they become much harder to germinate and the percentages come right down.
I store my seed in the fridge in brown paper envelopes - the main thing is that it can breathe and not become too dry.
Quite a bit about seed storage germination inhibitors and promotors in the link.

Here is a link that might be useful: Passiflora seed

Myles, yes, I've read those pages on your site--several times in fact. It's been my experience that dying any pasiflora seed greatly reduces its viability. To the point where if a seed source mentions that they've dried their seeds, I won't even bother.

I'd expect incarnata, lutea, affinis, mexicana, tenuiloba, foetida var. gossypiifolia to all respond to stratification to some degree or other, since they're all exposed to freezing weather over the winter months. But obviously incarnata and lutea, being the northern-most ranging, probably derive the most benefit from it.

I have never been able to germinate the local incarnata seeds without cold moist stratification. Dried seeds germinated fine a year later, nearly 100%, but only if stratified moist for 60 days. The need for stratification of incarnata seeds probably depends on the climate in which they were collected.