182 BETULACEAE 
hop-like group of bracts, while in Corylus the bracts form a much 
divided fringe-like collar which encloses the oval nut. 
Pistillate flowers not in catkins. 
Bract of the involucre halberd-shaped . . . Carpinus 
Bract of the involucre pointed, oval . . . . Ostrya 
Bracts of the involucre much incised . . . .  Corylus 
Pistillate flowers in catkins. 
Scales of pistillate flowers falling early . . . Betula 
Seales persistent, . . .-.: S :) 2 2. oe 
1. CARPINUS, L. 
Small tree with smooth gray bark and very compact wood. Stems fur- 
rowed. Staminate catkins long, drooping and scaly. Pistillate, two 
flowers to each leaf-like bract, the latter in a spiral around a pro- 
longed stem. Nut small ovoid. 
C. caroliniana, Walt. (Fig. 1, pl. 26.) AmeErrIcAN HoRNBEAM. BLUE 
Beecu. A small tree, generally growing under the protecting cover of 
larger trees. Leaves long ovate with sharp notches, the teeth extending 
to the spine. Terminal spine very acute. In shady and damp places, 
throughout our area. April-May. 
2. OSTRYA, Scop. 
Small tree, in general resembling the hornbeam. The leaves are less 
prolonged and the cluster of fertile flowers and fruit resembles an 
elongated hop flower. 
O. virginiana, (Mills.) Willd. (Fig. 2, pl. 26.) Hor Horneseam. 
Tronwoop, Staminate flowers scaly, the scales extending to the branch. 
Nut oblong ovoid, small. In dryer places than Carpinus. 
3. CORYLUSSL: 
Shrubs with broad leaves, staminate flowers in a scaly catkin, scales 
reaching the branch, expanding before the leaves. Pistillate flowers in 
small groups also appearing before the leaves. The involucre surround- 
ing the seed becomes a strong rough envelope to the seed or nut. 
1. C. americana, Walt. (Fig. 5, pl. 26.) Hazex Nur. Leaves 
broad, rounded, with rather fine serrations. The involucre large and 
spreading with deeply lacinated borders. Throughout our area. 
2. C. rostrata, Ait. (Fig. 4, pl. 26.) Braxep HazeL Nut. Leaves 
less round than the previous species, extremity narrowly pointed, ser- 
rations coarse. The involucre of the nut contracts to a long narrow 
neck and is covered with hairs. Throughout our area. 
4; BETULA, EL. 
Trees and shrubs, outer bark generally in layers of horizontal fibers. 
Bark and young twigs aromatie. Both kinds of flowers expand before 
the leaves. Staminate catkins drooping, each scale covering 3 flowers. 
