31/32 of actual size Hazilberts. Left to right: No. 3, No. 5, No. 4, No. 2
No. 1 Hazilbert about 9/15/42. Note almost identical size and shape of this actual photograph of No. 1 compared to predetermined size and shape in drawing made almost one year previous to photograph. Plant had not produced any nuts prior to crop of 1942
Chapter 5
HAZELS AND/OR FILBERTS
There is a certain amount of confusion in the minds of many people regarding the difference between filberts and hazels, both of which belong to the genus Corylus. Some think them identical and call them all hazels dividing them only into European and American types. I see no reason for doing this. "Filbert" is the name of one species of genus Corylus just as "English walnut" is the commercial name of one of the members of the Juglans family. There is as much difference between a well-developed filbert and a common wild hazelnut as there is between a cultivated English walnut and wild black walnut.
For ordinary purposes the nuts sold commercially, whether imported or grown in this country, are called filberts while those nuts which may be found growing prolifically in woodlands and pastures over almost the whole United States but which are not to be found on the market are called hazelnuts. This lack of commercialization of hazelnuts should be recognized as due to the smallness of the nut and the thickness of its shell rather than to its lacking flavor. Its flavor, which seldom varies much regardless of size, shape or thickness of shell, is both rich and nutty. The three main food components of the hazelnut, carbohydrate, protein and oil, are balanced so well that they approach nearer than most other nuts the ideal food make-up essential to man. The English walnut contains much oil and protein while both chestnuts and acorns consist largely of carbohydrates.
One salient feature which definitely separates the species Corylus Americana or wild hazel, from others of its genus, is its resistance to hazel blight, a native fungus disease of which it is the host. Controversies may occur over the application of the names "hazel" and "filbert" but there is no dispute about the effect of this infection on members of genus Corylus imported from Europe. Although there is wide variety in appearance and quality within each of the species, especially among the European filberts, and although filberts may resemble hazels sufficiently to confuse even a horticulturist, the action of this fungus is so specific that it divides Corylus definitely into two species. Corylus Americana and Corylus cornuta, through long association, have become comparatively immune to its effects and quickly wall off infected areas while filbert plants are soon killed by contact with it. Hybrids between filberts and hazels will usually be found to retain some of the resistance of the hazel parent.