Summary
A new genus of Acanthaceae, Diceratotheca, is described from Thailand. The genus is characterised by having unique pollen combined with several unusual morphological characters, of which the 2-spurred anther thecae also appear to be unique within Acanthaceae. Phylogenetic analyses show clearly that the genus belongs within the subtribe Ruelliinae. Further analyses, that include the largest available sample of species from other genera, including the species-rich Strobilanthes and Ruellia, demonstrate that the genus is not nested within other genera and a new genus is therefore required. Analyses show that, of the genera sampled, it is most closely related to Pararuellia Bremek., a herbaceous genus with which it appears to have little in common. The only species Diceratotheca bracteolata is known from a single site in NW Thailand and is probably critically endangered.
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Acknowledgements
The authors owe a special debt of gratitude to J. F. Maxwell (CMU) for collecting the original material, returning to the site for further material for sequencing and for providing information on its habitat and conservation status. Thanks are also due to Rosemary Wise for preparing the drawing and to the curators of CAS and CMU for the loan of specimens.
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Wood, J.R.I., Williams, B.P. & Scotland, R.W. Diceratotheca, a new genus of Acanthaceae from Thailand. Kew Bull 67, 687–695 (2012). https://doi.org/10.1007/s12225-012-9404-2
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DOI: https://doi.org/10.1007/s12225-012-9404-2