Curator and Director
Herbarium
Research Interests
• Collections management
• Systematics of grasses (Poaceae)
A taxonomic revision of Isachne in Madagascar – piecing together a global puzzle. Teisher combines morphological and molecular approaches using herbarium specimens to address long-standing problems in grass systematics. The genus Isachne R.Br. (Poaceae) contains 105 accepted species distributed across the tropics. Several species within the genus are narrowly endemic, and new species continue to be described, especially in South America and India. However, there has not been a comprehensive taxonomic revision of the genus published for over 150 years, and name applications have been highly inconsistent between treatments, so it is difficult to assess geographic ranges and relative rarity of the constituent species. Veldkamp (2016) lists the number of species of Isachne in Madagascar as either two or eight, citing the lack of a complete treatment of the genus for that country. The most recent such treatment was a partial one in Bosser (1969). Considerable collections of grasses have been made over the past decade throughout Madagascar, with a corresponding increase in the number of recognized species (Rakotomalala et al. 2021). A more current reconsideration of the species of Isachne with the added collections in the herbaria at P and MO would constitute a valuable improvement to our understanding of the genus in Africa as well as establish a strong foundation for a much-needed global revision. The student working on this project would combine morphological and anatomical work on herbarium specimens from Madagascar with a thorough investigation of the published taxonomic literature on Isachne. The student would develop skills in examining and handling herbarium specimens, using a microscope, downloading and analyzing geographic data from specimen databases, describing plants using scientific terminology, locating and understanding taxonomic literature, and applying the rules of botanical nomenclature. It is possible for the student participating in this project to receive co-authorship on a publication resulting from this work.
Reference:
• Bosser, J. 1969. Graminées des pâturages et des cultures Madagascar. Mém. ORSTOM 35: 271–273.
• Rakotomalala, N. H., Andriamanohera, M. A., Rabehevitra, D., Solofondranohatra, C. L., Jeannoda, V. H., Ranaivojaona, A., ... & Vorontsova, M. S. 2021. Grasses of the Isalo National Park, Madagascar–checklist, origins, and significance. Madagascar Conservation & Development.
• Veldkamp, J. F. 2016. New status and combinations for the two East African taxa of Isachne R. Br.(Gramineae). Botany Letters, 163(1), 19-24.