Finding the last missing white oak hybrid from the Iberian Peninsula (Fagaceae, Quercus , sect. Quercus )

The genus Quercus is widely known for its ability to hybridize among sympatric species, especially inside the same Section. The Iberian Peninsula is a major phylogeographic hotspot for oak diversity, with almost all possible combinations of hybrids already described inside sect. Quercus. In this work we present the remaining hybrid not yet described among the Iberian white oaks; we found it in one of the few areas (in the Southern Iberian Peninsula) where both parents (the Algerian oak, Q. canariensis, and the Lusitanian dwarf oak, Q. lusitanica) grow sympatrically. We provide a description of this nothotaxon (which we named Quercus xgaonae) based on morphological characters related to leaf shape and trichome analysis. This work emphasizes the practice of natural history and encourages botanists to keep up their work on describing plant diversity in a major hotspot like the Mediterranean Basin.