Oaks of the World

-- Section Quercus, Sub-Section Lobatae, Erythromexicanae, Group Eugeniaefolia

-- This name (eugeniifolia or aff. eugeniifolia) was first applied to a species forming populations in Mexico and in Costa Rica; but in 2021 S. Valencia-A. demonstrated that the northern trees were different from the southern ones and that, consequently, they were actually two distinct species; the southern populations retained the name, while those from the North received the name Q. delgadoana.

-- Closed to Q. salicifolia of which it is often considered as a synonym, but the latter differs in : a different geographical origin (central/south Mexico to Panama vs Costa Rica), the leaf length ((4-20(25) cm vs 7-15 cm), the angle of the veins with the midrib (45° to 60° vs 75°), the petiole length (more than 5 mm vs 2-4 mm);