414 Betulacee—Betula. 
Orver CVIII.—BETULACEA 
Deciduous trees or shrubs with simple alternate stipulate 
leaves and moncecious flowers in catkins. Perianth none or 
bract-like. Flowers 2 or 3 together at the base of the bracts 
of the catkin. Stamens 2 to 5, with forked filaments and 
divergent anther-cells, or simple with connate anther-cells. 
Ovary 2-celled ; cells l-ovulate. Fruit a dry compressed lenti- 
cular often winged indehiscent nut, by abortion 1-celled and 
l-seeded; seed pendulous. This order is limited to the two 
following genera, whose species are estimated at about thirty- 
five. Theyare scattered over the north temperate zone and the 
mountains of South America. 
1. BETULA. 
Trees or shrubs in 
which the scales of the 
female catkin are thin 
and deciduous, and usu- 
ally trilobate. Stamens 
2. The species are con- 
fined to the northern he- 
misphere. The name is 
that used by the ancients. 
1. B. alba. Common 
Birch (fig. 214).—This 
graceful indigenous tree 
whose silvery white de- 
ciduous bark and slender 
branches render it so 
effective in a landscape, 
is represented by several 
varieties, differing mainly 
in the foliage from the 
ordinary form. But the 
first to claim our atten- 
tion is B. a. péndula, 
the Weeping Birch, one 
Seage of the most distinct and 
Fig, 214. Betula alba (Common Birch). desirable of this class of 
trees, being of moderate size when fully developed. The 
