0.86] CLASSIFICATION AND DESCRIPTION 



GENUS 85. COBYLTJS. 



149 



Low trees and large shrubs with simple, alternate, de- 

 ciduous, doubly serrate, straight-veined leaves. Flowers 

 insignificant, in catkins in early spring. Fruit an ovoid- 

 oblong bony nut, inclosed in a thickish involucre of two 

 leaves with a lacerated frilled border; ripe in autumn. 



* Leafy bracts of fruit forming a bottle-shaped involucre 2. 



* Leafy bracts not bottle-shaped. (A.) 



A. Involucre much longer than the nut 1. 



A. Involucre but little longer than the nut 3. 



1. C6rylus Americana, Walt. (WiLD 

 HAZELNUT.) Leaves roundish heart- 

 shaped, pointed, doubly serrate ; stipules 

 broad at base, acute, and sometimes cut- 

 toothed; twigs and shoots often hairy. 

 Involucre of the fruit open to the glo- 

 bose nut, the two leaf-like bracts very 

 much cut-toothed at the margin and 

 thick and leathery at the base. Merely 

 a shrub, 5 to 6 ft. high; quite common 

 throughout. 



C. Americana. 



2. C6rylus rostrata, Ait. (BEAKED HAZEL- 

 NUT.) Leaves but little or not at all heart- 

 shaped ; stipules linear-lanceolate. The in- 

 volucre, extending beyond the nut in a bract 

 like a bottle, is covered with stiff, short hairs. 

 Shrub, 4 to 5 ft. high. Wild in the same re- 

 gion as Corylus Americana, but not so abun- 

 dant. 



3. C6rylus Avellana, L. (EUROPEAN HA- 

 ZEL. FILBERT.) Leaves roundish-cordate, 

 pointed, doubly serrate, nearly sessile, with 

 ovate-oblong, obtuse stipules ; shoots bristly. 

 Involucre of the fruit not much larger than 

 the large nut (1 in.), and deeply cleft. A small 

 tree or shrub, 6 to 12 ft. high, from Europe ; 

 several varieties in cultivation. 



