Revision of Passiflora Subgenus Decaloba ... - Passion Flowers

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not until an analysis of the floral characters alone was undertaken that P.
coriacea and P. sexocellata became phenetically separable. Neighbor joining
analyses of both the qualitative and quantitative morphological characters also
support the recognition of these three taxa, with only two accessions
representing P. sexocellata (from Belize and México) appearing more similar to
P. megacoriacea than to other members of P. sexocellata from México and
Central America. The morphological cladistic analysis of the supersection
suggests that P. sexocellata and P. coriacea evolved from a common ancestor,
but that P. megacoriacea is more closely related to P. juliana and P. viridiflora.
Passiflora megacoriacea is placed with these species primarily based upon
characters relating to an increase in flower size (ovary size, operculum length,
etc.) that might be attributed to independent shifts to larger pollinators. However,
vegetative and reproductive characters other than those relating to overall flower
size (e.g., the shape of the flowers with an erect outer corona that is bent toward
the androgynophore, leaf shape, etc.) in P. megacoriacea suggest a closer
relationship with P. coriacea and P. sexocellata. Unfortunately, I was unable to
obtain material of P. megacoriacea for DNA sequencing, and a molecular
analysis that includes P. megacoriacea is needed and will likely settle the issue.
Nevertheless, it is clear in the molecular and morphological cladistic analyses
that P. coriacea and P. sexocellata are sister to each other (with a bootstrap
value of 100% in the DNA-based tree) and are both clearly diagnosable
cladospecies, and it is also likely that P. megacoriacea is closely related to these
two taxa.