Flower:

Slender, pale clusters (called catkins) up to 3 inches long of male pollen-bearing anthers hang from buds on 1-year-old branches. Female flowers are bud-like with a spray of red styles at the tip, on the same branch as male catkins, single in the axils or at the tip of the branch.

Leaves and stems:

Leaves are simple and alternate, 2½ to 4½ inches long, 1¼ to 3 inches wide, oval-elliptic or widest above the middle, with a long or short taper to a sharply pointed tip and a rounded to somewhat heart-shaped base. Edges are coarsely double-toothed and may have a few very shallow lobes. The upper surface is dark green and hairless to sparsely hairy, the lower is paler than the upper surface and hairy along major veins. Leaf stalks are ¼ to ¾ inch long and variously hairy to hairless and lack glandular hairs.

New twigs are greenish to yellowish tan to light brown and hairless or variously covered in minute hairs and becoming smooth the second year.

Older bark is light to dark brown with scattered white lenticels (pores), initially smooth but eventually developing a criss-cross pattern. Stems are multiple from the base, up to ¾ inch diameter at breast height (dbh), erect with ascending branches, spreading by rhizomes and may form small colonies or dense thickets.

Fruit:

Fruit is a round nut with a hard shell, 1/3 to ½ inch in diameter, enveloped in a stiff, green husk with up to 6 nuts in a cluster. The husk has a long tubular beak at least twice as long as the nut, is ruffled at the tip, and covered in bristly hairs.

Notes:

It strongly resembles the related American Hazelnut (Corylus americana), which has glandular hairs on twigs, leaf stalks and husks, and the husks lack the long beak. The two species' ranges overlap and may be found growing side by side, but Beaked Hazelnut is more common in moister sites and American Hazelnut in drier sites. There are 2 recognized subspecies of C. cornuta: subsp. cornuta, present in most of the species' range and described above, and subsp. californica, which is limited to the Pacific coastal region, has husks with beaks less than twice as long as the nut and usually has some glandular hairs.