Phylogenetic relationships in <i>Bulbostylis</i> (Abildgaardieae: Cyperaceae) inferred from nuclear and plastid DNA sequence data

Previous molecular phylogenetic analyses of the family Cyperaceae based on <i>rbc</i>L sequences showed <i>Bulbostylis</i> as paraphyletic, with <i>B. atrosanguinea</i> and <i>B. hispidula</i> forming a clade with <i>Nemum spadiceum</i>. On the contrary, phylogenetic analyses of the tribe Abildgaardieae based on nuclear (ITS ribosomal region) and plastid sequences (<i>trn</i>L-F region) showed <i>Bulbostylis</i> as monophyletic, although they only incorporated four species of <i>Bulbostylis</i> and none of <i>Nemum</i>. In this work, we presented a phylogenetic hypothesis of <i>Bulbostylis</i> based on a comprehensive sampling, including species from different continents for the first time. New sequences of <i>Abildgaardia</i>, <i>Crosslandia</i>, <i>Fimbristylis</i>, and <i>Nemum</i> were included to test the monophyly of <i>Bulbostylis</i>. In total, 84 sequences of both ITS and <i>trn</i>L regions were generated. Analyses were performed using Bayesian inference, maximum likelihood, and parsimony. Ancestral state reconstruction was performed using ML, MCMC, and parsimony methods. In all analyses, <i>Bulbostylis</i> resulted paraphyletic as <i>Nemum atracuminatum</i> is nested within it. Most American species of <i>Bulbostylis</i> grouped together, but relationships amongst them appeared poorly resolved. Ancestral state reconstructions of native distribution suggest an African ancestor of <i>Bulbostylis</i>, with at least three introduction independent events of the species in America. Morphological diagnostic characters such as the ‘style base permanence or detachment from the ripe achene’, and the ‘micromorphological patterns of the achene surface’ are homoplastic in this phylogenetic context, and therefore unsuitable to propose infrageneric groupings within the <i>Bulbostylis</i>.