Molecular systematics and evolutionary trends and relationships in the genus Jumellea (Orchidaceae): Implications for its species limits
Jumellea is an orchid genus centered on Madagascar but also occurs on some of the neighboring oceanic islands (the Mascarenes and Comoros) and in southern and eastern Africa. Prior to our study the genus contained ca. 55 morphologically distinct species, of which six are found
in the Comoros (three endemic, three shared with Madagascar), nine in the Mascarenes (four endemic, four shared with Madagascar), two in southern and eastern Africa (both endemic), and 41 species endemic to Madagascar. We perform Bayesian and parsimony phylogenetic analyses of Jumellea
based on combined chloroplast (matK, trnL-F, rps16, ycf1) and nuclear (nrITS) data from 60 specimens representing 47 species, four subspecies, and two varieties of Jumellea: (1) to assess the phylogenetic value of growth form, leaf, bract and lip shape, and
spur length, presently used for recognizing informal groups within the genus; and (2) to test the monophyly of some variable species (e.g., J. gracilipes, J. lignosa). We find no support for the informal groups of Jumellea, as all the characters tested are evolutionarily
labile. Jumellea lignosa (comprising J. lignosa subsp. lignosa, subsp. tenuibracteata, subsp. acutissima, and subsp. latilabia) is not monophyletic unless subsp. tenuibracteata is excluded. Jumellea gracilipes s. l. (including J. ambongensis,
J. imerinensis, and J. unguicularis) is polyphyletic. As a result, we resurrect these three latter species, and recognize J. lignosa subsp. tenuibracteata at species level. Furthermore, we propose new circumscriptions for the following species: the Comorian J.
arachnantha (including the Malagasy J. sagittata); the Reunionese J. exilis (including the Malagasy J. flavescens); the Reunionese J. recta (including the Malagasy Jumellea sp. 1); the Reunionese J. recurva (including the Malagasy J. pandurata);
and the Reunionese J. stenophylla (including the Malagasy J. gracilipes 2 and 3). Finally, Jumellea arborescens and J. maxillarioides are recorded from Madagascar and the Comoros. Finally, the number of species of Jumellea has now increased from 55 to 57:
seven species in the Comoros (four shared with Madagascar), nine species in the Mascarenes (four shared with Madagascar), two species in Africa, and 39 species, three subspecies, and two varieties restricted to Madagascar.
NEW SPECIES CIRCUMSCRIPTIONS;
WESTERN INDIAN OCEAN
Document Type: Research Article
UMR C53, Peuplements végétaux et Bioagresseurs en milieu tropical, Faculté des Sciences et Technologies, Université de La Réunion, 15 Av. R. Cassin BP 7151, 97715 SAINT-DENIS cedex 9,
Réunion, France, Département de Biologie et Écologie Végétales, Université d'Antananarivo, BP 906, Antananarivo 101, Madagascar;, Email: email@example.com
Bergius Foundation, The Royal Swedish Academy of Sciences, Department of Botany, Stockholm University, 10691 Stockholm, Sweden
UMR C53, Peuplements végétaux et Bioagresseurs en milieu tropical, Faculté des Sciences et Technologies, Université de La Réunion, 15 Av. R. Cassin BP 7151, 97715 SAINT-DENIS cedex 9, Réunion, France
Département de Biologie et Écologie Végétales, Université d'Antananarivo, BP 906, Antananarivo 101, Madagascar
Publication date: June 13, 2012
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