Corylus cornuta subsp. cornuta
Shrubs, open spreading, to (4–)6 m. Bark light brown, smooth. Branches ascending; twigs glabrous to sparsely pubescent, without glandular hairs. Winter buds containing inflorescences ovoid, 3–5 × 3–4 mm, apex acute. Leaves: petiole glabrous to moderately pubescent, without glandular hairs. Leaf blade ovate to obovate or narrowly elliptic, often nearly angular and lobulate near apex, 5–12 × 3.5–9 cm, base narrowly cordate to narrowly rounded, margins coarsely and often irregularly doubly serrate, apex usually distinctly acuminate; surfaces abaxially glabrous to moderately pubescent, usually pubescent on major veins and in vein axils. Inflorescences: staminate catkins usually in clusters of 2–3, 4.5–6 × 0.5–0.8 cm; peduncles mostly 0.5–2 mm. Nuts in clusters of 2–6; involucral tubular beak long, narrow, 2–3(–4) times length of nuts, densely bristly. 2n = 22, 28.
Phenology: Flowering very early spring.
Habitat: Moist to dry roadsides, edges of woods, fencerows, waste places, and thickets, or as understory in open woodlands
Elevation: 100–500 m
St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask., Ala., Colo., Conn., Ga., Idaho, Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mont., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Pa., R.I., S.C., S.Dak., Tenn., Vt., Va., Wash., W.Va., Wis., Wyo.
Like Corylus americana Walter, the beaked hazel (C. cornuta subsp. cornuta) is a weedy shrub and is sometimes considered a pest in carefully managed northern forests. The fruits are similar to those of C. americana, except that the surrounding bracts are connate into a long, narrow, tubular beak. Vegetative individuals of C. cornuta subsp. cornuta can be distinguished from C. americana by the absence of glandular hairs on the petioles and young twigs.