Nepenthaceae are a family of carnivorous plants mainly from Southeast Asia but with geographical
outliers reaching Madagascar and New Caledonia. They are highly collectable because of their attractive
and unusual morphology. Taxonomists have considerably increased the number of described species in
recent decades while other research has revealed remarkable ecological variation suggesting an adaptive
radiation. Despite considerable public and scientific interest, limited phylogenetic knowledge hinders
further understanding of this interesting family. Incorporating many previously unsampled species and
using high throughput sequencing this study investigates their phylogeny, biogeography, evolutionary
history and conservation status.
I perform phylogenetic analyses using a target capture approach with 353 low copy nuclear loci
and 197 samples representing 151 species covering all the main geographic regions and taxonomic
sections and with multiple samples of geographically widespread species. Supermatrix and summary
coalescent analyses produce similar results, revealing two major Southeast Asian lineages, with subclades
geographically defined to a high degree. My phylogenetic analyses are then used to investigate the
biogeographical history and evolutionary radiation of the family, with ancestral reconstructions and
investigations of diversification rate and species-pair trait divergence. I find an increase in diversification
rate between two major Southeast Asian clades and investigate this in relation to altitude, substrate and
range-size. Biogeographical analysis indicates an out-of-Borneo pattern for several major lineages, with
little internal migration to this island. Finally, I explore phylogenetically informed conservation
prioritisation of Nepenthes, using IUCN Red List assessments combined with my phylogenetic results to
perform a HEDGE analysis, additionally investigating regional patterns and the relationship between
evolutionary distinctiveness and extinction risk.