54 KEY AND FLORA 
long, thick-shelled, with a very sweet kernel. Wood hard and heavy. 
Common in rich, damp soil W. 
4. C. alba K. Koch. Mocxer Nout, Wuite-Heart 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. ovata. 
5. C. cordiformis K. Koch. Pianut, Swamp Hickory. A me- 
dium-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, 
common in the Middle States. ; 
17. BETULACEZ. Biren Famity 
Trees or shrubs with alternate, simple, petioled leaves, with 
usually deciduous stipules. Flowers moncecious in cylindrical 
or subglobose catkins. Staminate catkins drooping ; flowers 
1-3 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-like; 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. Hazentnut. A shrub 2-5 ft. high; young 
twigs and petioles covered with brownish, stiff hairs. Leaves not 
very thin, round-cordate, acute or slightly taper-pointed, irregularly 
toothed, nearly smooth above, downy below. Involucre longer than 
