A tale of North and South America: time and mode of dispersal of the amphitropical genus Munroa (Poaceae, Chloridoideae)

摘要: Plant disjunctions have provided some of the most intriguing distribution patterns historically addressed by biogeographers. We evaluated three hypotheses that been postulated to explain these [vicariance, stepping-stone dispersal and long-distance (LDD)] using Munroa, an American genus grasses with six species a disjunct between desert regions North South America. The ages clades, cytology, ancestral characters areas were investigated in order establish relationships among species, determine time divergence its main lineages, understand further biogeographical evolutionary history this genus. Bayesian inference recovered M. pulchella as sister rest. Molecular dating area analyses suggest Munroa originated America late Miocene–Pliocene (7.2 Mya; 8.2–6.5 Mya). Based on results, we postulate two events modelled current Munroa: first from 8.2–6.5 Mya) second (1.8 Mya; 2–0.8 Mya) Arid conditions Neogene Quaternary climatic oscillations probably advantageous for establishment populations Munroa. did not find any relationship ploidy events, our character shifts associated seedling establishment, such habit, reproductive system, disarticulation rachilla, shape texture glume, important reaching new areas. © 2015 Linnean Society London, Botanical Journal Society, 2015, 179, 110–125.