Create your own conference schedule! Click here for full instructions

The Virtual Conference is located at

Abstract Detail


Pejhanmehr, Mersedeh [1], Yorkston, Mitsuko [2], Morden, Clifford [3].

Low Genetic Diversity in the Highly morphological Diverse Sida fallax Walp. (Malvaceae) throughout the Pacific.

Sida fallax Walp. (`ilima) (Malveae; Malvoideae; Malvaceae) is native to the Pacific area and is extensively distributed throughout this region. It is noteworthy that Sida fallax is the most widespread and variable taxon of Malvaceae in Hawaiian Islands and it occurs with diverse morphological forms in different habitats from Hawaii Island to Midway Atoll. Morphological variation exists both within and among populations, particularly in plant stature, leaf size and shape, degree of pubescence and inflorescence characters. Sida fallax can be found in a variety of dryland to mesic coastal to upland habitats and communities from 0 to 2,000 m elevation. Two extreme ecotypes are recognized in this species including the beach ecotype that is a prostrate shrub with small, pubescent leaves and the mountain ecotype that is an erect shrub with larger, nearly glabrous leaves. Based on herbarium specimens and researcher reports, only the coastal ecotype is observed in other Pacific islands. The range of morphological and ecological diversity in Sida fallax suggest that this species requires further biosystematics investigation. The purpose of this study is assessing variation and from that determine if multiples species should be recognized. To do this, an individual from each of 26 populations throughout the Hawaiian Islands and 12 individuals from different parts of Pacific region were collected. Total genomic DNA was extracted, non-gene coding nuclear and chloroplast regions including ITS, ETS and psbA-trnH were amplified, and sequences were compared using Bayesian phylogenetic analyses. The nuclear and plastid phylogenies represented S. fallax as a single species throughout its distribution regions. All S. fallax individuals from throughout the geographic range formed a single polytomy with few base pair differences.
The low genetic differentiation between various S. fallax populations and the unresolved pattern showed that dispersal by ocean-drifted fruits can maintain genetic cohesion of the species across Pacific Ocean. In addition, the morphological diversification in ecotypes of Sida fallax in Hawaiian Islands was not reflected in these phylogenies suggesting a recent radiation, allopatric distribution on different islands, and reflected habitat differences in single islands.

Log in to add this item to your schedule

1 - University Of Hawaii At Manoa, Botany, St. John Plant Science Laboratory – 101, 3190 Maile Way, Honolulu, HI, 96822, United States
2 - University of Hawaii at Manoa, 3190 Maile way, Room 101, Honolulu, HI, 96822, United States
3 - University Of Hawaii, School Of Life Sciences, 3190 Maile Way, Honolulu, HI, 96822, United States

Sida fallax
Pacific region
Hawaiian Islands  
Morphological variation.

Presentation Type: Poster
Session: P3, Systematics Posters
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 5:00 PM(EDT)
Number: P3SY002
Abstract ID:264
Candidate for Awards:None

Copyright © 2000-2021, Botanical Society of America. All rights reserved