The Phylogeny and Biogeography of Phyla nodiflora (Verbenaceae) Reveals Native and Invasive Lineages throughout the World

Abstract

Phyla nodiflora is an herbaceous perennial and an enigmatic species. It is indigenous to the Americas but is considered a natural component of the flora in many areas and a weed in others. Our aim was to circumscribe the native range of P. nodiflora, to explore dispersal mechanisms and routes and to test the hypothesis that P. nodiflora is native outside of the Americas. Determining whether distributions are natural or human-induced has implications for decisions regarding weed control or conservation. We undertook phylogenetic analyses using sequence variation in nuclear DNA marker ITS (Internal Transcribed Spacer) for a global sample of 160 populations of P. nodiflora sourced from Asia, Australia, central America, the Mediterranean, southern North America, South America and Africa. Analyses included maximum likelihood, maximum parsimony, a Bayesian estimation of phylogeny and a parsimony network analysis which provided a genealogical reconstruction of ribotypes. We evaluated phylogenies against extensive historical and biogeographical data. Based on the sequences, 64 ribotypes were identified worldwide within P. nodiflora and considerable geographic structure was evident with five clades: one unsupported and the remaining weakly supported (bootstrap support ranging from 52% to 71%). Populations from central and southern North America formed the core area in the indigenous range and we have detected at least three native lineages outside of this range. Within Australia P. nodiflora is represented by at least one native lineage and several post-European introductions. Phyla nodiflora is one of the few species in the family Verbenaceae to have a pan-tropical native distribution, probably resulting from natural dispersal from America to Africa then to Australasia. However, it has also undergone human-mediated dispersal, which has obscured the native-origin of some ribotypes. These introductions present a risk of diluting the pan-tropical structure evident in this species and therefore they have important conservation implications.

Unsuccessful introduced biocontrol agents can act as pollinators of invasive weeds: Bitou Bush (Chrysanthemoides monilifera ssp. rotundata) as an example

“…Deliberate introductions of a self‐incompatible species alleviates mate limitations that may be inherent in species that have arrived via natural, long‐distance dispersal events (Pannell et al., ). In addition, if pollinators that have coevolved with the plant species are added to the mix (this study), or generalists are present (European honeybee, Apis mellifera L.) then allogamous invasive species are able to proliferate (see Phyla canescens , a successful cosmopolitan species, Gross, Fatemi, Julien, McPherson, & Van Klinken, ).…”

Evaluating Growth and Physiological Responses of a Medicinal Plant Phyla nodiflora to Salinity

“…Phylla nodiflora (syn. Lippia nodiflora) belongs to the Verbenaceae family and is a creeping herbaceous plant distributed in many countries around the world, such as Asia, Australia, Central-South America, the Mediterranean, and Africa [11,12]. The whole plant is used in traditional medicine to treat various diseases such as asthma, bronchitis, knee pain, gonorrhea, hemorrhoids, heart disease, hepatitis, and fever [13].…”

Special Issue: Plant Genetics and Biotechnology in Biodiversity

“…Three more specific contributions present the possibilities, limitations, and achievements related to improving crops by exploiting different kinds of genetic resources, landraces in the case of tomatoes [5], wild gene pools for wheat [6], and mutants for barley [7]. Research articles also offer varied examples of the study of molecular and/or phenotypic diversity in trees (olive and grape) [8,9] as well as herbaceous crops (maize, rice, and wheat) [10][11][12] and wild species [13]. These papers illustrate how recent knowledge about DNA-based analytical tools is converted into useful applications for the description, understanding, and utilization of the genetic diversity.…”