Quercus × ludoviciana Sarg.

Quercus × ludoviciana is a naturally occurring hybrid from the southeastern United States, which has flourished and attracted attention in collections worldwide. Over the years there has been some confusion regarding the hybrid’s parentage, but it is now accepted to be a cross of Q. phellos (Willow Oak) and Q. pagoda (Cherrybark Oak). Willow Oak influence is evident in the leaf outline, though, as would be expected in a hybrid, there is considerable variation in leaf shape. The foliage is deciduous, or semi-evergreen in cultivation (Edwards & Marshall 2019), and spring colouring is reported to be spectacular, with copper-tinted young leaves. Lammas growth is said to be even better, when young leaves in ‘lovely hues of bronze and coral red, contrast superbly with the dark green older leaves.’ Lammas growth leaves are also larger and more strongly lobed (Muir 1978). The bark is described by le Hardÿ de Beaulieu & Lamant (2010) as being closer to Q. phellos, though some specimens tend towards Q. pagoda.

When he described it in 1913, C.S. Sargent considered the hybrid’s parents to be Q. phellos and Q. pagodifolia (a synonym of Q. pagoda), as he found it growing together with these two species in ‘low, inundated woods,’ and detected characteristics of these putative parents in the specimens he described. However, the taxon Q. pagoda has had an unstable history and was at times considered to be a variety of Q. falcata. This has led to some confusion with Q. × subfalcata (Q. phellos × falcata), and one can find many references where Q. × ludoviciana is defined as being the cross of Q. phellos and Q. falcata (van Hoey Smith 2001; Palmer 1948). These two hybrids are indeed difficult to differentiate: according to le Hardÿ de Beaulieu & Lamant (2010), it is the presence of falcate lobes (typical of Q. falcata) that distinguishes Q. × subfalcata from Q. × ludoviciana, whereas Tammie Russell has stated that what sets them apart is Q. falcata’s rounded leaf base: it is found in Q. × subfalcata but not in Q. × ludoviciana, where the leaf base is acute, like in Q. pagoda (Russell 2014). (It is worth noting that Q. × subfalcata Trel. is a later homonym of Q. subfalcata Freidrich, published in 1883 to describe a fossil; according to (Oak Names Database 2025), a proposal to conserve Trelease’s name is in preparation.)

According to The Hillier Manual (Edwards & Marshall 2019), Louisiana Oak was introduced to cultivation in 1880. This may refer to a tree growing in Borde Hill Garden in West Sussex, UK, identified in 1932 by Alfred Rehder, Curator of the Herbarium at the Arnold Arboretum, as being Q. × ludoviciana. Rehder would have been familiar with the newly described hybrid, as C.S. Sargent had been Director of the Arnold Arboretum and the specimen from St Landry Parish (see below) was stored in the Arnold’s Herbarium. The Borde Hill tree came from the famed Rovelli nursery in Pallanza, Italy, but there is no record of the name it was sent under (Bean 1976). It measured 27 m × 68 cm dbh in 2025 and is the UK champion for height. Several trees in the UK have a larger girth, the largest at Royal Botanic Gardens, Kew, planted in 1935, 25.3 m tall and with a trunk 130 cm in diameter in 2022 (The Tree Register 2025). Surprisingly, it was grafted from the Borde Hill tree, which it has amply outgrown in girth. It has shown remarkable growth, its diameter practically doubling from 27 cm to 51 cm between 1967 and 1978 (Clarke 1988).

A specimen at Caerhays, Cornwall, UK was presumed to be of the same origin and was 21 m × 71 cm in 2006 (Williams 2016), but has since died (The Tree Register 2025). One imagines that Borde Hill may have been the source for the trees propagated by the Hillier Nurseries, one of which was dispatched to Douglas Cook’s Eastwoodhill Arboretum in New Zealand, where it flourished and has become one of the star attractions of the collection, and the champion in cultivation. Received in 1949 and planted in 1951, it has displayed an impressive growth rate and excellent form, and stands 27.2 m tall with a trunk 165 cm in diameter and an average canopy spread of some 40 metres (M. Kleiters pers. comm. 2025, Eastwoodhill 2025). Another of Hillier’s specimens is growing in Trompenburg Gardens in Rotterdam, the Netherlands, where Dick van Hoey Smith was surprised that it was not hardier: ‘Since both parents are quite hardy, it is quite incomprehensible that this offspring has to be protected in childhood.’ Received in 1968, it was not planted till 1970 and was later transplanted to a less exposed spot in 1973 (van Hoey Smith 2001). This may be the reason The Hillier Manual rates it as hardy to H5, though the hardiness of the parent species would warrant a higher rating (USDA Zone 5, equivalent to H7).

Quercus × ludoviciana is by all accounts a striking and attractive tree. For Bean (1976), ‘it is one of the most ornamental of the oaks, with healthy, glossy foliage richly tinted when it unfolds and remaining on the tree without withering until late in the autumn’; for The Hillier Manual, ‘A most attractive, large, semi-evergreen tree of vigorous habit’. The hybrid’s remarkable growth rate is to be expected in a descendant of Q. pagoda, which is known to be ‘quick off the mark’ (R. Russell, pers. comm. 2019). When the late Bob Berry was cataloguing the trees at Eastwoodhill in 1976, he noted that the St. Landry Oak was a fine specimen and ‘the most vigorous oak at Eastwoodhill’ (Berry 1997) – he also collected acorns from it, and several of these F₂ offspring grow in his Hackfalls Arboretum, the largest with a trunk 102 cm in diamenter in 2020 (Hackfalls Arboretum 2020). Charles Williams describes the specimen at Caerhays as having ‘especially beautiful bark,’ and notes that ‘it tends to drop all its leaves in spring just as or even before the new growth emerges’ (Williams 2014).

The epithet ludoviciana means ‘pertaining to Ludovicus’, the Latin version of the name Lewis (Ludwig in German and Louis in French). In botanical nomenclature, it has been used to describe plants found near St. Louis, Missouri—the best known example is Artemisia ludoviciana – or more commonly in the US state of Louisiana – e.g. Carya × ludoviciana. Both places were named after a French king by the name of Louis, but not the same one: St. Louis for Louis IX, who reigned in the 13th century, while Louisiana was named for Louis XIV, who occupied the same throne some four centuries later.

In the case of oaks, the epithet first appeared as ludoviciana and was used by Alphonse de Candolle in his Prodromus (1864), where it is assigned to a variety of Q. falcata found in Louisiana. His Latin description hints that it may indeed be a hybrid: ‘An hybrida quaedam?’ (‘Or a hybrid?’). Trelease (1924) treated this name as a synonym of Q. falcata. The accepted name Q. × ludoviciana was established by C.S. Sargent in 1913 based on a specimen he collected with R.S. Cocks, from a tree they found 15 miles west of the town of Opelousas, in central Louisiana. Opelousas is the seat of the parish of St Landry (Louisiana is divided into parishes, like most other states in USA are divided into counties). ‘St Landry Oak’ became one of the common names of Q. × ludoviciana, also derived from a French historical figure: Landry (Landericus) was a 7th-century bishop of Paris (Cameron 2019).

The other common name is ‘Louisiana Oak’, which seems somewhat arbitrary as 25 oak species and 11 recognised hybrids are native to that state (Oak Names Database 2019).