Grass identification workshop in Madagascar

Find out how Kew staff helped local scientists in Madagascar learn to identify unique and endangered species of grasses.

Grassland n Central Madagascar, Maria Vorontsova / RBG Kew, 2014

Unique and endangered species of grasses (Poaceae) can be documented only if local scientists have access to specialist knowledge and powerful microscopes. 

The flowers of grasses are tiny and hidden inside multiple bracts (modified leaves). The arrangement of the flowers and bracts into aggregate inflorescences define the grass species and genera. Unique terminology is used to distinguish the different kinds of bract and scientific literature on Poaceae taxonomy uses this terminology in identification keys and structure diagrams. It is difficult to identify grasses without familiarity with this terminology, so it is difficult to learn grass species without specialist training. Access to a good microscope is also needed. Recent biodiversity assessments and conservation policy decisions in Madagascar have not included any information on the grass species because it has not been possible to identify the grasses. 

Brachiaria subrostrata is endemic to the high plateau regions of Madagascar. A line of long white hairs on the upper glume and lower lemma is only found on two species, both of them restricted to Madagascar. 

Maria Vorontsova and Steve Renvoize, botanists from Kew's Herbarium, travelled to Madagascar in February 2012 to teach a two week course on grass identification to 12 local scientists from nine different institutions. Everyone made and processed collections together on the field trips and this material was used in the workshops. The workshop sessions covered evolution of the grasses, terminology, and spikelet structure of different subfamilies. Everyone dissected spikelets under a microscope and made drawings of the different spikelet parts. 

We hope this course has encouraged local botanists to collect grasses. More collections will enable us to define the endemic species and their distributions, and this information will allow the endemic species to be protected. This work is part of Maria Vorontsova’s research on Madagascar grasses and will contribute towards a taxonomic treatment of all Madagascar Poaceae. 

Maria and Steve would like to thank the Bentham-Moxon Trust for financial support of this project.