54 KEY AND FLORA 
long, thick-sheled, with a very sweet kernel. Wood hard and heavy. 
Common in rich, damp soil W. 
4. C. alba K. Koch. Mocker Nut, Wuite-Heartr Hickory. A 
large tree 70-100 ft. high, with close, rough bark; catkins, twigs, 
and under surfaces of the leaves downy and resinous-scented when 
young. Leaflets 7-9, oblong-lanceolate or obovate-lanceolate, taper- 
pointed. Fruit globose or nearly so, with a very thick, hard husk; nut 
with 4 ridges toward the apex, very thick-shelled, with a small, sweet 
kernel. On rich hillsides. Wood much like that of C. orata. 
5. C. cordiformis K. Koch. Piegnur, Swamp Hickory. A me- 
diuin-sized tree, with rather smooth bark. Leaflets 7-11, lanceolate 
or oblong-lanceolate. Fruit not large, husk thin; nut globular, with 
a short point, very thin-shelled; kernel extremely bitter. Moist soil, 
conunon in the Middle States. 
17. BETULACEZ. Biren FamiLy 
Trees or shrubs with alternate, simple, petioled leaves, with 
usually deciduous stipules. Flowers moncecious in cylindrical 
or subglobose catkins. Staminate catkins drooping ; flowers 
1-35 in the axil of each bract; calyx none or membranous 
and 2-4-parted; stamens 2-10, distinct. Pistillate catkins 
drooping, spreading, or erect and spike-lke; flowers with or 
without a calyx; ovary solitary, 1—-2-celled; ovules 1-2 in each 
cell. Fruit a 1-celled nut or a key.* 
I. CORYLUS L. 
Shrubs with prominently veined, cut-toothed leaves, which 
are folded lengthwise in the bud. Flowers expanding before 
the leaves. Staminate flowers in slender, drooping catkins ; 
stamens 8, anthers 1-celled. Fertile flowers several in a 
cluster or in very short catkins at the ends of the twigs of 
the season ; ovary incompletely 2-celled; style short; stigmas 
2; bractlets 2, becoming enlarged and inclosing the single 
bony nut at maturity.* 
1. C. americana Walt. Hazetnur. A shrub 2-5 ft. high; young 
twigs and petioles covered with brownish, stiff airs. Leaves not 
very thin, round-cordate, acute or slightly taper-pointed, irregularly 
toothed, nearly smooth above, downy below. Involucre longer than 
