Quercus rysophylla hybrids

On this page we discuss hybrids of Loquat-leaf Oak that have arisen both in gardens and in the wild. For a full discussion of the species, see the Quercus rysophylla entry.

Hybrids arising in gardens

Since the value of Quercus rysophylla as an ornamental has been appreciated and since it started to bear acorns in cultivation, many plants have been raised from its seed, usually giving rise to hybrids. As these often come from gardens with large oak collections, it is often not easy to determine the other parent. Perhaps the first time a hybrid was raised from a tree growing in the UK was in 1996, when the large tree at Sir Harold Hillier Gardens fruited for the first time, and a hybrid resulting from this seed is grown there. Even before it started to fruit in Europe, hybrids were grown in the USA. Seed distributed from cultivated plants at Yucca Do Nursery, now The John Fairey Garden, Texas, gave rise to hybrids now growing at RHS Garden Rosemoor (Devon, UK), among others. The male parent of these was suspected to be Q. falcata, but this has never been proven. A similar hybrid was found at Arboretum Chèvreloup, France. In the USA, David Creech commented that the largest tree of Q. rysophylla at Stephen F. Austin State University, Nacogdoches, Texas, produces some ‘crazy hybrids,’ while David Richardson stated that it can hybridise with Q. nigra or Q. pagoda (Coombes 2016). A hybrid, possibly with Q. rubra, at Buckingham Palace, London, reached 13 m × 26 cm in 2021 and was described as a handsome tree (The Tree Register 2025). At the Royal Botanic Gardens Victoria in Melbourne, Australia a seedling of the Q. rysophylla at Hoddle’s Creek, evidently hybridised, put on remarkable growth of about 1 m per year for the first five years, later slowing to about half a metre annually (P. Berbee, pers. comm. 2025).

A selection of the most desirable garden hybrids have been given cultivar names; these are treated individually below.

Hybrids arising in the wild

Fairey and Schoenfeld (1994) reported the discovery in 1989 of a single tree of an evergreen oak ‘well over 80 ft tall’ which they called the “Spinoza oak”, growing with Quercus rysophylla and Q. sartorii, and it has been suggested that it is a hybrid between these species. It was growing in a deep canyon about 50 km south of Monterrey. The leaves are similar to those of Q. rysophylla but are edged with 1 cm aristas similar to those of Q. sartorii and are bright red-purple during the growing season. It was introduced to cultivation and came true from seed, reaching 3 m tall by 1994. Plants were distributed by Yucca Do in the early 1990s. A tree at Stephen F. Austin State University, Nacogdoches, Texas, reached 4.5 m tall in 2015. A plant of what is probably the same hybrid is grown by Bob McCartney at the Citywide Arboretum, Aiken, South Carolina, where it is called Q. rysophylla × canbyi, although it was originally received from Yucca Do as Quercus La Espinosa (‘or something like that’). This plant produces acorns that have found their way to other collections. As this is a single specimen and likely to be pollinated by another species, any offspring should be treated as suspect: seed from this plant appears to have produced a hybrid with Q. nigra at Chevithorne Barton, Devon, UK. Another plant raised from this seed has made a bushy evergreen tree 2.9 m tall at Arboretum des Pouyouleix, France, and appears to be a triple hybrid, also possibly with Q. nigra. In 1991, Guy Sternberg found an oak in the San Isidro Canyon, southwest of Santiago, that was originally thought to be a hybrid of Q. rysophylla with Q. canbyi. A specimen in the herbarium of The Morton Arboretum of this collection has been determined as Q. rysophylla × sartorii.

Another candidate for a potential natural hybrid is Quercus tenuiloba. Described by Muller in 1936 from Alamar, Galeana, Nuevo León, it was accepted as a species by Valencia Ávalos (2004) and regarded as a synonym of Q. xalapensis by Romero Rangel (Romero Rangel 2006). The type specimen, C.H. & M.T. Muller 1125 (Missouri Botanical Garden Herbarium MO-143904), shows a shoot bearing acorns ripening from the previous year (i.e. biennial) and foliage similar to that of Q. xalapensis or Q. sartorii, with long-aristate teeth. The leaves, however, show impressed veins and a distinctly cordate base, both characters of Q. rysophylla. In 1994, D.E. Breedlove annotated this as ‘probably Q. rysophylla × xalapensis.’ According to Leccinum Garcia (pers. comm. 2015), similar plants are also found in Tamaulipas. Further field work is necessary to determine the status of this taxon. The presence of Q. xalapensis in Tamaulipas has not been confirmed.