Abstract Detail

Systematics

Svoboda, Harlan [1], Ballard Jr, Harvey E [1].

Untangling the passionflowers: Phenetic and cladistic studies in Dysosmia (Passiflora, Passifloraceae).

One of the most unusual and taxonomically difficult groups in the passionflower genus, section Dysosmia (Passiflora, Passifloraceae), has perplexed botanists for nearly 200 years. Although revised in the past, a lack of statistical rigor has led to increased confusion and obscure taxon boundaries. To investigate morphological affinities and potential relationships in section Dysosmia, phenetic and cladistic analyses were carried out. The study was based on vegetative morphological characters and included a linear discriminant analysis, principal coordinates analysis, cluster analysis, and cladistic analysis. The results revealed that there are at least three major groups in the section. In each of the analyses the glabrous, red-fruited taxa (the P. ciliata group) always formed a distinct cluster, while taxa once belonging to a separate subgenus (the Dysosmioides group) formed another phenetic cluster. A third cluster (the P. foetida group) was an assemblage of pubescent, green-fruited taxa. A putative fourth group of pubescent, red-fruited taxa was not well supported as being a distinct aggregation in Dysosmia and instead usually sorted with the P. foetida group. We propose that individuals that are glabrous throughout the plant body correspond to the P. ciliata group, whereas those that bear pubescence correspond to the P. foetida group—the exception being the Dysosmioides taxa which have noticeably leafier stipules and involucral bracts and bear no glands on the leaf surfaces.

1 - Ohio University, Department of Environmental and Plant Biology, 315 Porter Hall, Ohio University, Athens, OH, 45701, USA

Keywords:
Passiflora
Dysosmia
Passifloraceae
phenetics
cladistic analysis
morphology
cluster
ordination
PCoA
LDA.

Presentation Type: Oral Paper
Session: 41, Basal Rosids & Rosids I
Location: 101/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 9:30 AM
Number: 41007
Abstract ID:262
Candidate for Awards:None