Quercus humboldtii Bonpl.

This is the only species of Quercus in South America. It is found at high elevations in Colombia, and in Panama only occurs close to the border with Colombia. It is widely planted as a street tree in Bogotá (Cameron 2017). It was introduced to cultivation in Europe from a collection in the Jardín Botánico José Celestino Mutis, Bogotá, Colombia, and grows at Iturraran Botanical Garden, Spain. It also grows at Tregrehan, Cornwall, UK, collected from a street tree in Bogotá.

Quercus humboldtii was described by French botanist Aimé Bonpland in 1809 and named after the German naturalist Alexander von Humboldt, who accompanied him on a journey to South America. They collected specimens of this species in the Bogotá region of Colombia.

Bonpland described three oak species from what is today Colombia, and all three were recognised by De Candolle (1864) and later by Trelease (1924), who grouped them in his series Andinae. C.H. Muller (1942), however, found that Bonpland’s tree species were indistinct and synonymised Q. tolimensis and Q. almaguerensis under Q. humboldtii. He claimed the species were described as separate because few specimens were available for classification: ‘The few collections at the disposal of Humboldt and Bonpland and later of de Candolle were insufficient to reveal their identities as one polymorphic species differing only in the luxuriance of the foliage and persistence of tomentum along the midrib beneath.’ More species were described by later authors, but all are currently considered synonymous with Q. humboldtii, though many point out that it is very diverse in morphology. Two common names are used for the species in Colombia,’roble rosado’ (pink oak) and ‘roble blanco’ (white oak), apparently in reference to the different colour of the heartwood. According to Hernando Rodríguez Correa (pers. comm. 2024), it is quite possible that there may be a link between previously described species and some of the genetic groups that have been studied recently (Cameron 2025).