Revision of Passiflora Subgenus Decaloba ... - Passion Flowers

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addition, Reiseberg and Brouillet (1994) argue that species derived through local
speciation will follow a sequence of polyphyly→paraphyly→monophyly and insist
that a criterion of monophyly for species recognition is inadequate and that it is
more logical to view the phylogenetic status of a species as a property that will
vary over time (Rieseberg & Brouillet, 1994). Undoubtedly, P. suberosa and the
other species of supersection Cieca are rapidly evolving as compared to other
groups of plants and even other groups within Passiflora (as illustrated by Shawn
Krosnick's work on Passiflora supersect. Disemma, pers. com.). It is quite
possible that Passiflora suberosa has been caught in the polyphyletic to
paraphyletic stage of speciation, but further molecular work is needed to justify
this hypothesis. Nevertheless, it should be noted that the monophyly of the other
18 species of supersection Cieca was supported in my analysis (see below).
Species Concepts
The phylogenetic species concept sensu Wheeler and Platnick was primarily
employed in this study (Wheeler & Platnick, 2000). That is, the smallest
aggregation of populations or lineages diagnosable by a unique combination of
character states were recognized as "species.” However, other species concepts
such as the biological species concept (Mayr, 1942), phenetic species concept
(Sokal & Crovello, 1970) and autapomorphic concept (Donoghue, 1985; Mishler,
1985) were also considered and frequently proved useful. In the phenetic
analyses of the P. suberosa and P. coriacea complexes, I looked for gaps in the
pattern of variation and used sets of morphological characters in species
delimitation. I also considered the inability to interbreed, along with other
evidence, as an indication that P. itzensis is a good species. In addition, nearly