JUGLANDACEAE OF THE UNITED STATES. 45 
are actually of hybrid origin, while others, like the tree of 
Dr. Schneck, and those occurring spontaneously in Europe, 
are probably only aberrant forms respectively of nigra and 
regia. Quite recently Professor Sargent* has described 
and figured what he regards as a hybrid between regia and 
cinerea, the twigs of which are much more like those of 
regia than those of either of the supposed spontaneous 
hybrids that I have seen, though with more elongated buds 
and sometimes a little pubescent in the axils of the notched 
leaf scars. In the same article mention is made of several 
artificial hybrids produced in California by Mr. Luther Bur- 
bank, between Californica and both nigra and regia. Twigs 
of the first of these hybrids, for which I am indebted to 
Mr. Burbank, are downy and closely resemble those of 
nigra except that their gray terminal buds are usually twice 
as long as broad; while the twigs of the second are very 
stout, glabrous, and with large globose loosely gray tomen- 
tose buds. 
EXPLANATION OF PLATES ILLUSTRATING JUGLANDACEAE. 
The half-tones are from photographs taken by the 
author or contributed by correspondents whose donations 
are indicated in the description. The other plates are from 
drawings made by Miss Grace E. Johnson under the 
author’s direction. Twigs, fruits and nuts are of natural 
size; twig details X 3. 
Plate 1.—Hicoria Pecan, an old tree 16 ft. in circumference, near Mt. 
Carmel, Il. Photographed by Dr. Schneck. 
Plate 2.— Bark of Hicoria Pecan, Caruthersville, Mo. 
Plate 3.— Group of Hicoria aquatica, Campbell, Mo. Photographed by 
James Oxley. 
Plate 4.— Bark of Hicoria aquatica,— one of the trees of Plate 3. 
Plate 5.— Hicoria minima, Mt. Carmel, Ill. Photographed by Dr. 
Schneck. 
Plate 6.—Bark of Hicoria minima, St. Louis, Mo. 
Plate 7.— Bark of Hicoria glabra, Ithaca, N. Y. Photographed by 
Professor Rowlee. 
* Garden and Forest, vii. 484; Silva, vii. 114. 
Tr A Rs ey 
