Phylogeny and biogeography of the hollies (Ilex L., Aquifoliaceae)

<p>The holly genus, <em>Ilex</em> L., in the monogeneric Aquifoliaceae, is the largest woody dioecious genus (&gt;664 spp.), with a near‐cosmopolitan distribution in mesic environments. We constructed a phylogeny based on two nuclear genes, representing 177 species spread across the geographical range, and dated using macrofossil records. The five main clades had a common ancestor in the early Eocene, much earlier than previously suggested. <em>Ilex</em> originated in subtropical Asia and extant clades colonized South America by 30 Ma, North America by 23 Ma, Australia by 8 Ma, Europe by 6 Ma, and Africa by 4 Ma. South and North America were colonized multiple times. <em>Ilex</em> also reached Hawaii (10 Ma) and other oceanic islands. Macrofossil and pollen records show the genus has tracked mesic climates through time and space, and had a wider distribution before late Miocene global cooling. Our phylogeny provides a framework for studies in comparative ecology and evolution.</p>