Quercus marilandica blackjack oak Fagaceae QUMA2; R, cp, lp, ro, sm, sv, t, x;

Dipartimento di Scienze della Vita, Università di Trieste - Progetto Dryades - Picture by Andrea Moro - Meise, Nationale Plantentuin van België, Jardin Botanique National de Belgique, Brabant, Belgique/België, - Image licensed under a Creative Commons Attribution Non Commercial Share-Alike 3.0 License

Dipartimento di Scienze della Vita, Università di Trieste – Progetto Dryades – Picture by Andrea Moro – Meise, Nationale Plantentuin van België, Jardin Botanique National de Belgique, Brabant, Belgique/België, – Image licensed under a Creative Commons Attribution Non Commercial Share-Alike 3.0 License (Accessed 5/2017).

Quercus marilandica is a tree to 15 m tall; red oak group, (subgenus Erythrobalanus), bark black, fissures blocky, roots associated with ectomycorrhizal fungi (Decker and Boerner 1997).

Leaves alternate, wide near top, lobes shallow, 3-5, base rounded, leathery, shiny above tan hairy in veins below. 

Flowers green, monoecious, male in catkins, female flowers 1-few together; blooms April-May, wind pollinated. 

Quercus marilandica acorns. photos © Rebecca Dellinger-Johnston. International Oak Society. internationaloaksociety.org

Quercus marilandica acorns. photos © Rebecca Dellinger-Johnston. International Oak Society. internationaloaksociety.org

Fruit acorns to 1 cm long 1.8 cm wide (Flora of North America 1993+), tannin content high; cap about 2 cm wide, covering 1/2 acorn, scales large, matures 18 months, Sept.-Nov. Seeds dispersed by squirrels, blue jays and other animals that bury acorns. Acorns eaten by many birds and mammals that do not bury nuts (raccoons, foxes), (Martin et al. 1951; Wilson 1993). 

Wetland status: NL. 

Frequency in NYC: Infrequent, (NYS S3, U) NYS watch list. 

Origin: Native. 

Quercus marilandica. bark. ©2008 Will Cook. Carolina Nature. carolinanature.com

Quercus marilandica. bark. ©2008 Will Cook. Carolina Nature. carolinanature.com (Accessed 5/2017).

Habitat: sandy soil of south Staten Island. Tolerates dry, sterile soil, pH 4.6-5.6 (USDA, NRCS 2010), salt, drought. Intolerant of flooding, soil compaction, intolerant of shade, shade, index 2-4 (Hightshoe 1988). Can use up to 85% full sunlight for photosynthesis (saturation point) (Hicks and Chabot 1985). 

Notes: Deer and rabbits eat twigs, other animals eat buds (Martin et al. 1951). Foliage eaten by Gypsy moth larvae and other insects. (See Q. alba for insect predators). Included in a newly listed habitat type for New York State: Post Oak-Blackjack Oak Barrens, G2G3, NYS S1, U (Young and Weldy 2006). Occurring in Staten Island and Long island only.