874 ARBORETUM ET FRUTICETUM BRITANNICUM. 
1591. Q. Catesba‘i. 1592. Q. Catesba¥. 
pretty large, of a blackish colour, and partly covered with a fine grey dust, 
which is easily rubbed off between the fingers: they are contained in thick 
cups, swollen towards the edge, with the upper scales bent inwards. The 
leaves vary very little, as will be seen by jig. 1592., in which a@ represents a 
seediing of one year’s growth, and 6 a leaf from a plant two years old. 
§ vi. Nigre. Black American Oaks. 
Sect. Char., §c. Leaves wedge-shaped, or imperfectly lobed ; mucronated, but 
the mucros generally dropping off when the leaves have attained their full 
size. Leaves dying off of a blackish green, and in America frequently per- 
sistent. Bark black, and not scaling off. Fructification biennial. Nut 
ovate, with a persistent style, and sometimes marked with dark lines. —Trees 
from 20 ft. to 40 ft. high; and one of them, a miniature tree, often not 
exceeding 3 ft. in height. Rate of growth less rapid than in the preceding 
sections. ‘ 
¥ 21. Q.nrera LZ. The Black Jack Oak. 
Ldentification. Lin. Sp. Pl., 1413.; Michx. Quer., No. 12.; Pursh Fl. Amer. Sept., 2. p. 629. 
Synonymes. Q. marylaindica, &c., Rai; Q. ferruginea Michr. N. Amer. Syl. 1. p. 79. t. 20.3 Q. 
aquatica Lodd. Cat. ed. 1836; Barrens Oak, Amer. 
Engravings. Michx. Quer., t. 22, 23.; and our jig. 1593. 
Spec. Char., $c. Leaves wedge-shaped, somewhat heart-shaped at the base ; 
dilated, abrupt, and very slightly 3- 
lobed at the end; the middle lobe 
shortest, smooth above, rusty be- 
neath. Calyx hemispherical, with 
membranous scales. Nut roundish 
ovate. (Willd.) A low deciduous 
tree. New Jersey, Maryland, and 
Virginia. Height 20 ft. to 30 ft. 
Introduced before 1739. 
The Black Jack Oak, according to 
Michaux, is sometimes 30 ft. high, and 
8 or 10 in. in diameter, but commonly 
does not exceed half these dimensions. 
Its trunk is generally crooked; and it 
is covered with a very hard, thick, and 
deeply furrowed bark, which is black 
on the outside, though the inner bark 
is of a dull red. The head of the tree 
is broad and spreading, even in the 
