Phylogenetic Relationships in New Caledonian Palms (Arecaceae) with a Focus on Archontophoeniceae and Chambeyronia

Aubrey Cumberledge,* Craig F. Barrett, Mathilda Santee,* Donald R. Hodel, Department of Biology, West Virginia University, Morgantown, WV 26506

Field (Broad Category): Biology (Biological & Biochemical Sciences) 

Student’s Major: Biology 

New Caledonia is a tropical archipelago ~2,500 km off of Australia. It is home to a large number of endemic plant species, genera, and families, including ~40 palms. Palm subtribe Archontophoeniceae comprises five genera and occurs throughout tropical Australasia. Actinokentia, Chambeyronia, and Kentiopsis occur on New Caledonia, while Actinorhytis occurs on Papua-New Guinea and Archontophoenix occurs in Australia. Chambeyronia includes C. lepidota, C. macrocarpa, C. macrocarpa ‘Hookeri’, and C. macrocarpa ‘Houailu’. Phylogenetic relationships and species delimitation within this subtribe remain poorly defined. An earlier study placed Actinorhytis as sister to all other Archontophoeniceae, followed by a grade of Actinokentia, Chambeyronia, Kentiopsis, and Archontophoenix. We have increased taxon sampling and sequenced nuclear (RPB2 and PRK) and plastid DNA (rpl32-trnL spacer) from ~50 individuals representing most species. Our objectives are to: 1) resolve relationships among Archontophoeniceae, 2) clarify species within Chambeyronia; and 3) update taxonomy of the subtribe. Our analysis places Actinorhytis as sister to all other Archontophoeniceae, followed by clades of: 1) Kentiopsis piersoniana+Archontophoenix; 2) K. oliviformis; 3) C. macrocarpa ‘Houailu’; 4) K. pyriformis + Actinokentia divaricata; 5) K. magnifica; and 6) C. lepidota, C. macrocarpa, and C. macrocarpa ‘Hookeri’. Although branch support values are generally low, species of Kentiopsis receive moderate support in different regions of the tree, suggesting this genus may be paraphyletic. Our analysis also places Chambeyronia in two distinct positions, raising the possibility that C. macrocarpa ‘Houailu’ is a distinct species, and possibly a new genus. Additional markers will help resolve relationships and taxonomy within Archontophoeniceae. 

Funding: 

Program/mechanism supporting research/creative efforts: WVU's Research Apprenticeship Program (RAP) & accompanying HONR 297-level course