8. C. ovalis var. pallida
9. C. ovalis var. buckleyi
Doubtless many sub-species and variants are actually hybrids of obscure ancestry. Virginia has many such.
There is no reason to doubt that the hickories will grow anywhere ecological conditions approximate those of their native habitat. This is true in the Pacific coast states. Mr. Julio Grandjean, of Hillerod, Denmark, reports that there are several white hickories, C. alba or C. tomentosa, growing in the Horsholm Royal Park that were planted about 1790. There is no reason to believe that such northern species as the shellbark and shagbark would not also succeed. He reports winter-killing of pecans from southern sources. Inasmuch as extreme winter temperatures in Denmark are less than in some places where the pecan is grown here, it would appear that the more northern strains should succeed there, though lack of summer heat would prevent the maturing of nuts.
There appears to be much less interest in planting hickories on home grounds than the value of the species justifies. Only five states, Indiana, Ohio, Michigan, Pennsylvania and West Virginia, indicated any local interest. In each case the shagbark was the preferred species. Apparently we must still depend on the much-abused squirrel for the future of the hickory.
R. E. Hodgson of the Southeast Experiment Station, Waseca, Minn., reports 15 named varieties of hickory under test, but no evaluation of their worth can be made as yet.
Dr. R. T. Dunstan of Greensboro, North Carolina, has also a considerable number of hickory varieties under more advanced test. Results have been highly variable. He finds that Schinnerling has filled poorly; Whitney and Shaul are "Excellent growers and highly satisfactory bearers." Whitney, however, with a kernel of superb quality, cracks poorly and the husk is thick and heavy. Shaul is reported as having a rather thin kernel and cracking poorly, also.
Romig, that has been late in coming into bearing, is described as producing a large, handsome nut of good quality that cracks unusually well. Grainger, good in other respects, has borne light crops as also have Glover and Weschcke. Fox is described as superb in every respect except cracking quality.
Among the hicans, Burton is declared to be outstanding in vigor and health of tree, and production of good regular crops of delicious nuts that crack well.
It is interesting to note that in his extensive hickory experiments Dr.
Dunstan is using pecan stocks. He uses the bark-slot method of grafting
and hot wax compounded of 10 parts resin, 2 parts beeswax and one part
Kieselguhr. Both method and wax he finds highly successful.