Hybrids occur often in nature but still more are produced by collectors and in plant nurseries. However, not every species are able to cross pollinate and produce hybrids.
Since 1819 Passiflora caerulea is often cross-breed with P. racemosa. The hybrid P. caerulea ’Constance Eliott’ has partly white flowers and is just as frost resistant as the main species. P. caerulea also hybridize with P. quadrangularis and several other species.
Manual pollination should occur shortly after the styles in a newly open flower begin to bend towards the corona. At that time the stigmas are most susceptible.
The pictures show a F1 hybrid between Passiflora racemosa and P. caerulea. The green stigmas are a character in common with P. racemose, but otherwise it seems the genes from P. caerulea are the most expressed. See the irregular inner corona wreaths on the enlargement.
The enlargement at right shows the irregular inner corona wreaths
H. S. Heide-Jørgensen, March 2011.