ata,
H. glabra pallida, and H. glabra microcarpa, making sixteen well defined
hickories that have been described.

Nuts of all of these hickories are in the collection of "Edible Nuts of
the World" at Cornell University, with the exception of nuts of the
varieties H. glabra odorata and H. glabra pallida.

In addition to the sixteen described varieties and species of hickories
in America, we have an endless variety of hybrid forms, because
cross-pollenization seems to take place readily between hickories of
synchronous flowering time.

Five of the hickories: H. pecan, H. Texana, H. minima, H.
myristicaeformis, and H. aquatica belong to the open-bud group, while
the rest belong to the scale-bud group. The winter buds of the open-bud
group resemble the winter buds of the walnuts in a general way, and in
artificial hybridization experiments I seem to note a close relationship
between the open-bud hickories and the walnuts.

There is no more promising work for the horticulturist than crossing
hickories with walnuts, and crossing hickories with each other. Five
hundred years from now we shall probably find extensive orchards of such
hybrids occupying thousands of acres of land which is now practically
worthless. The hickories are to furnish a substantial part of the food
supply of the world in the years to come. At the present time wild
hickories held most highly in esteem are: H. pecan, H. ovata, H.
Carolinae-septentrionalis, and H. laciniosa. Several other kinds have
edible kernels, sometimes of excellent character, but not readily
obtained except by boys and squirrels, whose time is not valuable. In
this group we have H. alba, H. glabra, H. villosa, H. glabra pallida, H.
glabra odorata, H. glabra microcarpa, H. Mexicana, H. Buckleyi, and H.
myristicaeformis. In another group of hickories with temptingly thin
shells and plump kernels, we have a bitter or astringent pellicle of the
kernel. This group contains H. Texana, H. minima, and H. aquatica.
Sometimes in the bitter group we find individual trees with edible nuts,
and it is not unlikely that some of them represent hybrids in which the
bitter and astringent qualities have been recessive.

Among the desirable species of wild hickories there is much variation in
character, and selection of trees for propagation is in its infancy. One
reason for this has been the difficulty of transplanting hickories.
Another reason is the fact that hickories do not come true to parent