Abstract Detail

Systematics

Villanueva-Almanza, Lorena [1], Landis, Jacob [2], Ezcurra, Exequiel [3], Koenig, Daniel [4].

Reviving a century-old palm (Washingtonia) mystery using the power of Genotyping by Sequencing (GBS).

Between 1876 and 1889 extensive postal correspondence was held among a group of botanists in an attempt to clarify the distinction between two species of palms in the genus Washingtonia which would later be described as W. filifera and W. robusta. Closer inspection of the genus revives an old mystery: what is a species in Washingtonia. This widely distributed group of palms native to the Baja California peninsula, southern California, Sonora, and Arizona has been a taxonomic challenge due to a lack in type specimens, incomplete protologues, highly variable vegetative morphology, human dispersal, limited fieldwork in native populations, and poor representation in herbaria. We used Genotyping By Sequencing (GBS) data to understand population structure and delimit species. Using both a de novo and reference based approaches, we analyzed 173 Washingtonia individuals from 21 populations across its distribution range through multivariate and Bayesian methods. We found that Washingtonia populations were highly structured with four major geographic regions having unique haplotypes. Based on previous morphological results and the evidence herein we propose recognizing a single species of Washingtonia with four subspecies. Our results provide a robust phylogenetic analysis of Washingtonia settling a taxonomic debate that has lasted over a century.

1 - University Of California Riverside, Botany And Plant Sciences, 900 University Av. , Riverside, California, CA, 92521, United States
2 - University of California, Riverside, Botany and Plant Sciences, Riverside, CA, 92521, USA
3 - Univ. Of California, Botany & Plant Sciences, 900 University Ave., Riverside, CA, 92521, United States
4 - University of California Riverside, Botany and Plant Sciences, 900 University Av., Riverside, California, CA, 92521

Keywords:
Arecaceae
Baja California
Washingtonia
genetic structure
species delimitation
taxonomy.

Presentation Type: Oral Paper
Session: SYS1, Systematics I: Land plants, Gymnosperms to Rosids part 1
Location: Tucson H/Starr Pass
Date: Monday, July 29th, 2019
Time: 2:15 PM
Number: SYS1004
Abstract ID:345
Candidate for Awards:None