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<p>The circumscription of the tribe Vernonieae (Compositae) has been problematic due to the reorganisation of the polyphyletic genus <i>Vernonia</i> and the creation of many small genera. Recent phylogenetic studies have focused on the relationships within Vernonieae but few studies have explored the generic relationships within subtribe Piptocarphinae. Of note, some diagnostic features of Piptocarphinae are not unique to the subtribe and are found in other Vernonieae genera. In this study, we explored the phylogenetic relationships in Piptocarphinae, the genus boundaries in this subtribe and tested the infrageneric affinities of the paleate species, using previously published and newly generated nuclear ITS sequences for 65% of the genera of American Vernonieae. Results agree with previous phylogenetic studies, where nearly all subtribes are seemingly paraphyletic or polyphyletic. Piptocarphinae emerges as polyphyletic and should be reduced to contain only the monophyletic <i>Piptocarpha</i>, whereas <i>Critoniopsis</i> is monophyletic only if <i>Cuatrecasanthus</i> is included. We propose placing <i>Cuatrecasanthus</i> and <i>Joseanthus</i> in synonymy of <i>Critoniopsis</i>, resulting in eight new combinations: <i>C. chimborazensis</i>, <i>C. giannasii</i>, <i>C. flexipappa</i>, <i>C. kingii</i>, <i>C. lanceolatus</i>, <i>C. sandemanii</i>, <i>C. sparrei</i> and <i>C. trichotoma</i> and a new name, <i>C. boekei</i>. <i>Piptocoma</i> also resolves as non-monophyletic but no taxonomic recommendations are made, as few species have been sampled in phylogenies so far. We present a new combination in the genus <i>Piptocarpha</i>, <i>P. glomerulata</i>. The presence of paleae likely emerged independently at least three times in American Vernonieae. Paleate receptacles are present in three different series in <i>Piptocarpha</i> subg. <i>Piptocarpha</i>, which indicates that paleae have likely arisen twice in the evolution of <i>Piptocarpha</i>. Finally, a brief discussion about the adaptive function of paleae and pappus is provided.&#xa0;</p>

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Further disintegration of Piptocarphinae, an amplified concept of Critoniopsis and notes on the occurrence of paleae in Piptocarpha (Compositae: Vernonieae)

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  • 发表日期：

    2025年2月25日

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  • José Aguilar-Cano,
  • Carolina M. Siniscalchi,
  • Eve Lucas,
  • Panagiota Malakasi,
  • Benoît Loeuille

摘要

The circumscription of the tribe Vernonieae (Compositae) has been problematic due to the reorganisation of the polyphyletic genus Vernonia and the creation of many small genera. Recent phylogenetic studies have focused on the relationships within Vernonieae but few studies have explored the generic relationships within subtribe Piptocarphinae. Of note, some diagnostic features of Piptocarphinae are not unique to the subtribe and are found in other Vernonieae genera. In this study, we explored the phylogenetic relationships in Piptocarphinae, the genus boundaries in this subtribe and tested the infrageneric affinities of the paleate species, using previously published and newly generated nuclear ITS sequences for 65% of the genera of American Vernonieae. Results agree with previous phylogenetic studies, where nearly all subtribes are seemingly paraphyletic or polyphyletic. Piptocarphinae emerges as polyphyletic and should be reduced to contain only the monophyletic Piptocarpha, whereas Critoniopsis is monophyletic only if Cuatrecasanthus is included. We propose placing Cuatrecasanthus and Joseanthus in synonymy of Critoniopsis, resulting in eight new combinations: C. chimborazensis, C. giannasii, C. flexipappa, C. kingii, C. lanceolatus, C. sandemanii, C. sparrei and C. trichotoma and a new name, C. boekei. Piptocoma also resolves as non-monophyletic but no taxonomic recommendations are made, as few species have been sampled in phylogenies so far. We present a new combination in the genus Piptocarpha, P. glomerulata. The presence of paleae likely emerged independently at least three times in American Vernonieae. Paleate receptacles are present in three different series in Piptocarpha subg. Piptocarpha, which indicates that paleae have likely arisen twice in the evolution of Piptocarpha. Finally, a brief discussion about the adaptive function of paleae and pappus is provided.