Systematics and Evolution of the Genus Phoenix: Towards Understanding Date Palm Origins

Abstract

The date palm (Phoenix dactylifera L.)Date palm (Phoenix dactylifera) is an iconic crop of hot and arid regions of North AfricaNorth Africa, the Middle East and up to northwestern India. It is a member of the genus PhoenixPhoenix that constitutes a monophyletic group within the Coryphoideae subfamily, in the palm family. The genus Phoenix is composed of around 14 species whose native distribution is across the South of Europe, throughout Africa, the Arabian Peninsula and South Asia. Species boundaries and relationships are poorly understood owing to the morphological similarities between the species and their ability to hybridise. In this chapter, we review the past and present distribution of Phoenix species and aspects of their reproductive biologyBiology and genome dynamics. We then summarise the current state of knowledge of the taxonomyTaxonomy and phylogenyPhylogeny of PhoenixPhoenix and we outline the main challenges that have so far limited our understanding of the genus' systematicsSystematics and evolutionEvolution. We conclude with a roadmap to address these challenges by combining the extraordinary resource of specimens stored in herbarium collections and the power of high throughput DNA sequencing technologies.