JUGLANDACEAE OF THE UNITED STATES. 39 
kernel of fair flavor, but frequently abortive and replaced 
by a spongy mass.— Canada to the Great Lakes and 
Kansas, south to Texas and Florida, — in uplands.— PI. 
11, 14, f. 7-9, 15, f. 1-8, 18, f. 3-10. 
Occasional nuts, clearly of this species, occur with 
husks parted to the base and 7 to 12 mm. thick, suggesting 
hybridity with ovata, but I have not been able to study the 
trees from which they came. Other fruits suggest possible 
hybridity with the preceding species. 
In the autumn of 1894, Dr. J. Schneck, of Mt. Carmel, 
Il., and Mr. F. Reppert, of Muscatine, Iowa, sent to the 
herbarium twigs and fruit of bottom land trees that appear 
to be hybrids of this species with the Pecan.* The bark 
of the Iowa tree is described as being much like that of the 
Mockernut, while the tree of Dr. Schneck is smooth- 
barked, resembling the Pecan. So far as I have seen them 
the twigs of both might pass for those of alba except that 
the outer scales of the terminal buds are persistent, while 
the foliage, though intermediate, is strongly suggestive of 
that of the Pecan. The fruit is oblong, almost 2 in. long, 
the husk 6 mm. thick, parted nearly to the base, with 
strongly elevated margins to the segments, and rather per- 
sistent on the tree. The nuts are nearly as pale as in the 
Shagbark, conspicuously brown striped, slightly 4-celled 
at the very base, and with a wall only 1 mm. thick. As is 
usual in alba, they are upwardly attenuate, and frequently 
the kernel is abortive. It is not impossible that these 
hybrids represent the Juglans rubra of Lamarck (TIllustr. 
iii. 365, pl. 781, f. 4) and of Gaertner (Fr. pl. 89).— Pl. 
21, 23, f. 2-5. 
++ ++ Bark shaggy; outer bud scales persisting through the winter; 
nut angular and flattened from the side. 
= Fruit broader than long; husk moderately thick, not parted to the 
base. 
8. H. Mexicana (Engelm.) Britton. Carya Mexicana, 
Engelmann.— A medium sized tree; bark ‘* apparently 
* On one of these see Sargent, Silva, vii. 138. 
