Quercus marilandica Münchh.

Blackjack Oak is a tough oak that goes where others fear to tread. Adapted to poor soils, its presence in the wild is usually taken as an indicator of infertile ground. It even looks scrappy; its stout branches form an irregular outline, often with many short branches along the major limbs, creating a thicket-like appearance. Dirr (2009) described it as ‘a scrubby tree with a Hound-of-the-Baskervilles’ gothic habit’. But this wild character seems to owe more to its upbringing than its nature. Give it some coddling in favourable conditions, and it forms a pleasant ornamental tree with not unattractive autumn colour.

Quercus marilandica has an extensive distribution extending from New York’s Long Island and New Jersey in the northeast, southwards to Tampa Bay in Florida, across to southeastern Nebraska and down to central Texas in the southwest (Elwes & Henry 1913). It grows on dry sandy barrens or sometimes in the southwest on heavy clays (Sargent 1895). It is a dominant tree in savannahs and in forests adjacent to grasslands. In central Oklahoma and Texas, where the eastern deciduous forests grade into the drier western grasslands, it forms mixed stands with Q. stellata. It is co-dominant with Q. incana and Q. margaretta on midslopes of sandhills, where conditions are slightly more mesic than on xeric ridges that support Q. laevis. In the Pine Plains of New Jersey it is part of a community of dwarfed scrub oaks, growing in association with Q. ilicifolia and Pinus rigida. It is shade intolerant and slow growing, so it persists and becomes dominant only on sites too poor for faster-growing species. It bears seeds at a younger age than many associated arborescent oaks. In the Pine Plains of New Jersey, where fires recur at six- to eight-year intervals, Blackjack oaks survive by sprouting vigorously after being top-killed and producing viable seed on the sprouts in three to four years (Carey 1992).

Though tolerant of harsh conditions in the wild, Quercus marilandica responds well, in ornamental terms, to a more benign environment. For Sternberg (2004), it is ‘a ratty little fiddle-leaved shrub’ in inhospitable locations, but ‘when cultivated in good soil and given room, it can grow into a pleasant surprise with a perfect, symmetrical crown.’ Even in optimal conditions it is a slow grower, and it is difficult to transplant unless roots have been trained or pruned during early growth (cultivation in Air-Pot™ containers may help). Miller and Lamb (1985) dismiss it as ‘a poorly formed tree… slow growing and short lived,’ presumably referring to its characteristics in the wild, but Sternberg recommends it as ‘a trouble-free, long-lived, colourful landscape tree, loaded with character, that will take both heat and drought in stride,’ so long as it grows on any well-drained, acid soil.

Quercus marilandica was introduced to cultivation probably in the early 18th century, but the date is not documented. By 1739 it was being grown by Philip Miller at Chelsea Physic Garden in London (Aiton 1789). Elwes reported in 1910 that it was rare in cultivation, observing that it was usually short-lived in the climate of Great Britain and seldom displayed a healthy appearance, as the wood failed to ripen in autumn. He agreed, however, with François Michaux, who had written in 1842 that the species ‘deserves the attention of amateurs in Europe, for the singularity of its foliage’. For Elwes, Blackjack Oak ‘is worth a place in collections, on account of the large and curiously shaped leaves, which turn a brownish colour in autumn’. Autumn colour is unreliable in Britain (‘occasionally its leaves turn rich red in autumn, but more often brown’, wrote Bean in 1914), though less so in its native United States, where it is commended for its ‘russet-orange’ seasonal foliage (Wright 1992). According to Sternberg (2004), the leaves ‘turn great shades of crimson or orange in fall and are often marcescent through most of the winter.’ Dirr (2009), on the other hand, is lukewarm in his appraisal: ‘Fall color is at best yellow-brown, occasionally flashes of bronze-red, but not unattractive’.

Oak collectors have heeded Michaux’s and Elwes’ advice, and the species is found in most specialist collections. The tallest specimen in Britain is at the Savill Garden in Windsor Great Park, reaching 12.5 m × 29 cm in 2021, with a 1999 accession number but unrecorded planting date. At Kew, a tree accessioned in 1986 is of similar size: 12 m × 27 cm in 2022 (see photos below) (The Tree Register 2025). At Hackfalls Arboretum in New Zealand the species has lived up to its reputation of being slow: a tree planted in 1976 was just 5 m tall in 2014 (Hackfalls Arboretum 2025). At nearby Eastwoodhill Arboretum, however, a Blackjack Oak received from Hilliers has adopted a tall, narrow habit, likely as a result of competition from nearby trees, and measured 23.2 m × 1.6 m dbh (M. Kleiters, pers. comm. 2019).

The US national champion grows near Siler City, Chatham Co., North Carolina, measuring 29 m × 93 cm in 2014, with a bifurcated trunk (American Forests 20254; Grand Trees of Chatham 2025).

The wood of this oak is heavy, hard, and strong, but its value does not extend beyond its capacity to feed a fire, as it checks badly on drying, developing cracks and splits. Besides firewood and charcoal, it has little value for other purposes (Sargent 1895).

The species was first described by John Ray, apparently based only on its leaves, as he was not entirely sure it was an oak. It was one of numerous plant specimens received from the Colony of Maryland, sent to him by one of several collectors active in that area, sometime before 1704, when he published the description in the third volume of his Historia Plantarum (Ray 1704). He gave it the polynomial name ‘Quercus (fortè) Marilandica folio trifido, ad Sassafras accedente’ (‘Oak (perhaps) from Maryland, with three-forked leaves, similar to sassafras’). Ray’s polynomial was cited by Catesby in 1730. Linnaeus (1753) understood it to be a variety of Q. nigra, which he identified using only the Greek letter ß and citing Catesby. Other authors incorrectly interpreted this as Q. nigra var. marilandica L., and cited the name as the basionym of the current name. But Linnaeus did not give a nomen triviale to his variety of Q. nigra (Oak Names Database 2007–2008). As Ray’s and Catesby’s publications antedate the starting point of valid publication of scientific names, the first author to publish the binomial was Otto von Münchhausen in 1770, though he simply repeated Ray’s polynomial (citing Catesby), removing the parenthetical ‘perhaps’ and inserting a semicolon after marilandica. The epithet marilandica is of course arbitrary, given its wide distribution across many other states of the eastern USA. Ray described four other oaks with polynomials that included the term Marilandica, among the 225 names he proposed for plant specimens received from Maryland (Frick et al. 1987). It has been misspelt as ‘marylandica’ in several reference works, including Loudon (1838), Elwes & Henry (1910), and Bean (1916). Quercus marylandica Du Roi is in fact a synonym of Q. nigra.

The common name, Blackjack Oak, derives from Jack Oak, a term applied to scrub oaks whose wood was of little value except for fuel (Clapin 1902). This derogatory sense of ‘jack’ may possibly be derived from French, where jacques was used to refer to a peasant or a despicable or marginal man, and especially by nobles to refer to villains (del-Mancino et al. 2013). Blackjack or Black Jack was adopted in the Gulf states to refer to Q. marilandica, in reference to its bark. In the northern part of its distribution, the species was originally called Barren or Barrens Oak, due ot its occurrence in the pine barrens of that area (Michaux 1842). Jack Oak would also be adopted for another scrub oak, Q. incana, as Bluejack Oak, in this case alluding to the colour of the leaves.