× Quercus Willdenoviana Zabel is believed in Europe to be a hybrid of Quercus rubra and Quercus velutina.
13. [Quercus marilandica] Muench. Black Jack. Jack Oak.
Leaves broadly obovate, rounded or cordate at the narrow base, usually 3 or rarely 5-lobed at the broad and often abruptly dilated apex, with short or long, broad or narrow, rounded or acute, entire or dentate lobes, or entire or dentate at apex, sometimes oblong-obovate, undulate-lobed at the broad apex and entire below, or equally 3-lobed with elongated spreading lateral lobes broad and lobulate at apex, when they unfold coated with a clammy tomentum of fascicled hairs and bright pink on the upper surface, at maturity thick and firm or subcoriaceous, dark yellow-green and very lustrous above, yellow, orange color, or brown and scurfy-pubescent below, usually 6′—7′ long and broad, with a thick broad orange-colored midrib; turning brown or yellow in the autumn; petioles stout, yellow, glabrous or pubescent, ½′—¾′ in length. Flowers: staminate in hoary aments 2′—4′ long; calyx thin and scarious, tinged with red above the middle, pale-pubescent on the outer surface, divided into 4 or 5 broad ovate rounded lobes; anthers apiculate, dark red; pistillate on short rusty-tomentose peduncles coated like their involucral scales with thick rusty tomentum; stigmas dark red. Fruit, solitary or in pairs, usually pedunculate; nut oblong, full and rounded at the ends, rather broader below than above the middle, about ¾′ long, light yellow-brown and often striate, the shell lined with dense fulvous tomentum, inclosed for one third to nearly two thirds of its length in a thick turbinate light brown cup puberulous on the inner surface, and covered by large reddish brown loosely imbricated scales often ciliate and coated with loose pale or rusty tomentum, the upper scales smaller, erect, inserted on the top of the cup in several rows, and forming a thick rim round its inner surface, or occasionally reflexed and covering the upper half of the inner surface of the cup.
A tree, 20°—30°, or occasionally 40°—50° high, with a trunk rarely more than 1′ in diameter, short stout spreading often contorted branches forming a narrow compact round-topped or sometimes an open irregular head, and stout branchlets coated at first with thick pale tomentum, light brown and scurfy-pubescent during their first summer, becoming reddish brown and glabrous or puberulous in the winter, and ultimately brown or ashy gray. Winter-buds ovoid or oval, prominently angled, light red-brown, coated with rusty brown hairs, about ¼′ long. Bark 1′—1½′ thick, and deeply divided into nearly square plates 1′—3′ long and covered by small closely appressed dark brown or nearly black scales. Wood heavy, hard, strong, dark rich brown, with thick lighter colored sapwood; largely used as fuel and in the manufacture of charcoal.
Distribution. Dry sandy or clay barrens; Long Island and Staten Island, New York, eastern and southern Pennsylvania, and southern New Jersey to the shores of Matanzas Inlet and Tampa Bay, Florida, and westward through the Gulf states to western Texas (Callahan County) and to western Oklahoma (Dewey and Kiowa Counties), Arkansas, eastern Kansas, southeastern Nebraska and through Missouri to northeastern Illinois, southwestern and southern Indiana, and northeastern Kentucky (South Portsmouth, Greenup County, R. E. Horsey); rare in the north, very abundant southward; west of the Mississippi River often forming on sterile soils a great part of the forest growth; of its largest size in southern Arkansas and eastern Texas.
× Quercus Rudkinii Britt., with characters intermediate between those of Quercus marilandica and Q. Phellos, and probably a hybrid of these species, has been found near Tottenville, Staten Island, New York, at Keyport, Monmouth County, New Jersey, and at the Falls of the Yadkin River, Stanley County, North Carolina.
× Quercus sterilis Trel., believed to be a hybrid of Quercus marilandica and Q. nigra has been found in Bladen County, North Carolina.
× Quercus Hastingsii Sarg., believed to be a hybrid of Quercus marilandica and Q. texana, occurs near Boerne, Kendall County, and at Brownwood, Brown County, Texas.
× Quercus Bushii Sarg., believed to be a hybrid of Quercus marilandica and Q. velutina, although not common, occurs in eastern Oklahoma (Sapulpa, Creek County), Mississippi (Oxford, Lafayette County), Alabama (Dothan, Houston County, near Berlin, Dallas County, and Daphne, Baldwin County), Florida (Sumner, Levey County), and in Georgia (Climax, Decatur County).