=Juglans=.—The 15 species comprising this genus are found principally in the north temperate zone. Five species are native to North America and two are found in West Virginia. The English Walnut (_Juglans regia_, (L.)) which has been introduced and widely planted in the United States yields the valuable Circassian Walnut woods used in the manufacture of fine furniture as well as the walnuts sold in our markets.
Leaflets 11-17, often viscid-hairy; pith chocolate-brown; fruit elongated, sticky-hairy =J. cinerea, p. 59.=
Leaflets 13-23, not viscid-hairy; pith cream-colored; fruit globose, not sticky-hairy =J. nigra, p. 61.=
=Carya=.—The Hickory species number about 10, all of which are native to that part of North America lying east of the Rock mountains. At least 5 of these are found in West Virginia. _Carya microcarpa_, Nutt., not described herein is reported from Fayette County.
The Pecan Hickory (_Carya illinoencis_ (Wang.) K. K.), a southern species prized for its nuts, is occasionally planted.
a. Bark of trunk not deeply furrowed or shaggy; husk of fruit less than ⅛ inch thick.
Leaflets usually 5-7, glabrous beneath; the upper 2-2½ inches broad; kernel of nut sweet =C. glabra, p. 69.=
Leaflets usually 7-11, somewhat downy beneath, the upper 1-1½ inches broad; kernel of nut bitter =C. cordiformis, p. 71.=
a. Bark of trunk deeply furrowed or shaggy; husk of fruit more than ⅛ inch thick.
Leaflets 5-7, scurfy or pubescent; bark rough but not shaggy; buds densely hairy =C. alba, p. 67.=
Leaflets usually 7; nuts 1¼-2 inches long, pointed at both ends, dull white; bark shaggy =C. laciniosa, p. 65.=
Leaflets usually 5; nuts smaller, rounded or notched at the base, white, thin-shelled; bark shaggy =C. ovata, p. 63.=
The 6 genera and about 75 species belonging to this family are principally confined to the higher latitudes of the northern hemisphere. In North America there are 5 genera and about 30 species, of which the 5 genera and at least 9 species grow in West Virginia. The Common Hazelnut (_Corylus americana_, Walt.) and the Beaked Hazelnut (_Corylus rostrata_, Ait.) are both common shrubs of the State. The Smooth Alder (_Alnus rugosa_, (DuRoi) Spreng.) and the Hoary Alder (_Alnus incana_, (L.) Moench.) are both to be found, the former abundant along our streams, and the latter rare in upland swamps. _Alnus alnobetula_ (Ehrh.) K K. is also reported from Greenbrier, Fayette, and Randolph counties.