Quercus marilandica Fagaceae
Blackjack Oak, Jack Oak KWER-kus mar-i-LAN-di-ka
- Deciduous scrubby tree, may reach 30-40 ft (9-12 m) tall, rarely 70-90 ft (21-27 m), stout branches, often contorted, rounded or irregular outline, often a short trunk. Bark dark brown to blackish, deeply divided into nearly square plates 2.5-7.5 cm long. Leaves alternate, simple, thick, firm, roughly triangular, 15-17 cm long, broadly obovate, shallowy 3 or rarely 5-lobed at the very broad apex, margin entire or sparenly toothed, narrow base rounded or cordate, dark, glossy yellow-green above, brownish pubescence below; fall color brown or yellow, remain attached well into winter. Fruit (acorn) solitary or in pairs, nut rounded at both ends, enclosed 1/3 to 2/3 its length by a turbinate, light brown cup.
- Sun to light shade. Often found on soil of poor quality.
- Hardy to USDA Zone 6 Native range from New York to Iowa and south to Florida and Texas.
- marilandica: of Maryland.
- Oregon State Univ., North Willamette Research and Extension Center, Aurora