Tuesday, January 30, 2018

[Botany • 2018] Rediscovery of the Presumed-Extinct Dracaena umbraculifera || A Botanical Mystery Solved by Phylogenetic Analysis of Botanical Garden Collections

Dracaena umbraculifera  Jacq.

in Edwards, Bassüner, Birkinshaw, et al. 2018.
photograph by A. Lehavana  ||  stlpublicradio.org

Extinction is the complete loss of a species, but the accuracy of that status depends on the overall information about the species. Dracaena umbraculifera was described in 1797 from a cultivated plant attributed to Mauritius, but repeated surveys failed to relocate it and it was categorized as Extinct on the IUCN Red List. However, several individuals labelled as D. umbraculifera grow in botanical gardens, suggesting that the species’ IUCN status may be inaccurate. The goal of this study was to understand (1) where D. umbraculifera originated, (2) which species are its close relatives, (3) whether it is extinct, and (4) the identity of the botanical garden accessions and whether they have conservation value. We sequenced a cpDNA region of Dracaena from Mauritius, botanical garden accessions labelled as D. umbraculifera, and individuals confirmed to be D. umbraculifera based on morphology, one of which is a living plant in a private garden. We included GenBank accessions of Dracaena from Madagascar and other locations and reconstructed the phylogeny using Bayesian and parsimony approaches. Phylogenies indicated that D. umbraculifera is more closely related to Dracaena reflexa from Madagascar than to Mauritian Dracaena. As anecdotal information indicated that the living D. umbraculifera originated from Madagascar, we conducted field expeditions there and located five wild populations; the species’ IUCN status should therefore be Critically Endangered because < 50 wild individuals remain. Although the identity of many botanical garden samples remains unresolved, this study highlights the importance of living collections for facilitating new discoveries and the importance of documenting and conserving the flora of Madagascar.

Keywords: Botanical garden, Dracaena reflexa, Dracaena umbraculifera, extinction, living collections, Madagascar, Mauritius, phylogeny reconstruction

The original illustration of Dracaena umbraculifera from Jacquin (1797) 

Dracaena umbraculifera in Ile Sainte-Marie in full flower
photograph by A. Lehavana 

Christine E. Edwards, Burgund Bassüner, Chris Birkinshaw, Christian Camara,  Adolphe Lehavana, Porter P. Lowry, James S. Miller, Andrew Wyatt and Peter Wyse Jackson. 2018. A Botanical Mystery solved by Phylogenetic Analysis of Botanical Garden Collections: the Rediscovery of the Presumed-Extinct Dracaena umbraculifera. Oryx. DOI: 10.1017/S0030605317001570 

MoBot scientists use DNA testing to bring an African plant out of extinction news.stlpublicradio.org/post/mobot-scientists-use-dna-testing-bring-african-plant-out-extinction
Presumed-extinct 𝘋𝘳𝘢𝘤𝘢𝘦𝘯𝘢 𝘶𝘮𝘣𝘳𝘢𝘤𝘶𝘭𝘪𝘧𝘦𝘳𝘢 rediscovered! Botanical mystery solved by phylogenetic analysis of botanical garden collections  bit.ly/2ANB5WN