Summary
The genus Isoglossa Oerst. (Acanthaceae) is revised in west Africa, with particular emphasis upon the Cameroon Highlands. Four species are recognised, including Isoglossa dispersa I. Darbysh. & L. J. Pearce newly described here, and a second new species for which further flowering material is required before description, here called Isoglossa sp. A. Lectotypes are chosen for I. glandulifera Lindau and I. nervosa C. B. Clarke and the status of the latter species in relation to the eastern African I. membranacea C. B. Clarke is discussed. The habitat, ecology and conservation status of each species are considered, and gregarious mass-flowering is reported in I. dispersa.
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Acknowledgements
We would like to thank Martin Cheek and two anonymous reviewers for comments on a draft of this manuscript, Katherine Challis for providing the Latin diagnosis for Isoglossa dispersa, Andrew Brown for the excellent illustrations and Quentin Luke and Pierre Haba for allowing us to use the photographs reproduced here. Pierre Haba, Pepe Haba, Alphonse Goman, Cece Jérôme and colleagues in the Environment team at Rio Tinto Guinea (SIMFER) are also thanked for providing excellent information on the populations of Isoglossa dispersa and Brachystephanus oreacanthus at Simandou and Mt Béro; it is hoped that with Rio Tinto’s assistance these populations and the important forest ecosystems within which they are found can be safeguarded for the future. The following are thanked for providing a loan of/access to the Isoglossa collections at their respective institutions: Robert Vogt (B), Jonathan Gregson (BM), Elmar Robbrecht (BR), Geoffrey Mwachala (EA), Hans-Helmut Poppendieck (HBG), Marc Pignal (P) and Jean-Michel Onana (YA).
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Darbyshire, I., Pearce, L. & Banks, H. The genus Isoglossa (Acanthaceae) in west Africa. Kew Bull 66, 425–439 (2011). https://doi.org/10.1007/s12225-011-9292-x
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DOI: https://doi.org/10.1007/s12225-011-9292-x