Petenaeaceae, a new angiosperm family in Huerteales with a distant relationship to Gerrardina (Gerrardinaceae)

Authors

  • MAARTEN J. M. CHRISTENHUSZ fls ,

    Corresponding author
    1. Botanic Garden and Herbarium, Finnish Museum of Natural History, PL7 (Unioninkatu 44), University of Helsinki, 00014 Helsinki, Finland
    2. Department of Botany, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
      E-mail: maac@nhm.ac.uk
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  • MICHAEL F. FAY fls ,

    1. Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
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  • JAMES J. CLARKSON,

    1. Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
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  • PETER GASSON fls ,

    1. Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
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  • JULIO MORALES CAN,

    1. Herbario, Centro de Estudios Conservacionistas (CECON), Universidad de San Carlos de Guatemala, Avenida La Reforma 0-63, zona 10, 01010 Guatemala Ciudad, Guatemala
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  • JORGE B. JIMÉNEZ BARRIOS,

    1. Herbario, Centro de Estudios Conservacionistas (CECON), Universidad de San Carlos de Guatemala, Avenida La Reforma 0-63, zona 10, 01010 Guatemala Ciudad, Guatemala
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  • MARK W. CHASE fls

    1. Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
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E-mail: maac@nhm.ac.uk

Abstract

Petenaea cordata (from northern Central America) was first described in Elaeocarpaceae and later placed in Tiliaceae, but most authors have been uncertain about its familial affinities. It was considered a taxon incertae sedis in the Angiosperm Phylogeny Group classification (APG III). A recent collection was made in Guatemala, and analysis of both rbcL and atpB in the large Soltis et al. angiosperm matrix, the most completely sampled study published to date, indicated a moderately supported relationship to Tapiscia (Tapisciaceae, the only member of the newly recognized order Huerteales in this matrix; 81% bootstrap support). We then conducted a more restricted analysis using the Bayer et al. rbcL/atpB matrix for Malvales supplemented with the other genera of Huerteales from published studies. Our results indicate a distant, weakly supported sister-group relationship to the African genus Gerrardina (Gerrardinaceae; Huerteales). After comparison of the characters cited in the literature and an examination of herbarium material of both genera, we could find no obvious synapomorphies for Gerrardina and Petenaea or any other relationship of the latter, and we therefore propose the new monogeneric family, Petenaeaceae. The polymorphic order Huerteales now comprises four small families: Dipentodontaceae, Gerrardinaceae, Petenaeaceae and Tapisciaceae. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164, 16–25.

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