Corylus Avellana (Linn.). Common hazelnut.—Leaves roundish, heart-shaped, pointed, coarsely and unevenly serrate; husk bell-shaped, spreading, with a fringed or deeply cut margin. The original form of this nut is supposed to have been ovate or oval, but with a plant indigenous to such a wide range of climate and country, and one that has been so long under cultivation,—running wild in many localities where it is not a native,—it would be very difficult at this time to determine its primary botanical characters. A common shrub or small tree throughout the greater part of Europe and Asia.

Corylus Colurna (Linn.).—Constantinople hazel. Leaves roundish ovate, heart-shaped; husk double, the inner one divided into three deeply cleft divisions, the outer with many long, slender, curved segments, giving to the calyx or husk a fringed appearance, but leaving the end of the nut fully exposed (Fig. 39). Nuts small, and for this reason rarely cultivated. Native of Asia Minor, where the tree attains a hight of from fifty to sixty feet. It is, however, hardy in France and England, and was introduced into the latter country some three hundred years ago, probably by Clusius, who received either nuts or plants from Constantinople, hence its present name.

There are several other hazels and filberts, so distinct from the two common European types that botanists have, in a few instances, been inclined to elevate them to the rank of species, and among these I may name Corylus heterophylla, or various-leaved filbert, from eastern Asia, also the Corylus ferox, or spiny filbert, which has a long and deeply cut or fringed husk. It is a native of the Sheopur mountain in Nepaul. But from the two common European species, C. Avellana and C. Colurna, and their hybrids, many hundreds of varieties have been raised, and from among these we may readily select a dozen possessing all the distinct and estimable properties to be found in this genus of nut-bearing plants; to multiply names without securing anything of intrinsic value, is but a waste of time and labor on the part of the cultivator.

As we have no popular varieties of American origin, I am compelled to consult European catalogues in making a selection of those most promising for cultivation here, and this is, perhaps, an advantage, inasmuch as our transatlantic cousins have had a long experience and abundant opportunities for determining the merits of the varieties they recommend. If hardiness and adaptation to our soil and climate are to be taken into account, in making a selection, then we may fail for the want of experienced guides, as it is undeniable that very few persons in this country have ever attempted to conduct extended experiments in the cultivation of either the native or European species and varieties of the hazel.

Taking this view of the situation, I shall avail myself of the small but select list of varieties given in that standard work, "The Dictionary of Gardening," edited by Mr. George Nicholson, of the Royal Gardens, Kew, England.