A gaa 
Betulaceae. Birch Family. aga 
Trees, or less commonly shrubs, with bark which separates into two layers 
and alternate leaves with scaricus deciduous stipules. Flowers of two sexes 
in separate catkins, both borne on the same tree, appearing in early spring, 
with or before the leaves. Perianth present or none. Staminate flowers 1-3 
in the axil of each bract, stamens usually several or numerous, anthers 2-cham- | 
bered,, dehiscing longitulinally. Pistils 3 in each bract, ovary «-chambered , 
style branches <. Fruit a l-chambered, l-seeded nut or NUtLO tS Hee et 
O Fruit a conelike catkin, the,scales of which are 
PY aie. tt like a fleur-de-lis and fall from 
'\ the central axis in late summer A, Betula 
O Fruit a small cone with persistent woody wedge- 
4 Shaped scales 2. Alnus 
-B Betula L. Birch, 
Trees or shrubs with smooth bark Consvicuously marked with transverse 
lenticels, in some species separating into very thin papery sheets. Perianth 
present in staminate flowers, 2-4 lobed, wanting in the Distillate, Stamens 
2, the filaments branched, cach bearing a single anther, Ovaries sessile, 
Nutlets small, compressed, winged, bearing the versistent stignas, falling 
with the bracts, leavin;; the »ersistent rachis, 
© Leaves commonly 5-8 cm. long, acuminate, rounded to 
truncate or cordate at the base; cones usually 
4 d=4 cme long or more f. rife 
© Leaves commonly 2-4 cm. long, mostly obtuse or obscurely 
acuminate, or else blunt and rounded, mostly cuneate 
a Lat base; cones usually 2-2.5 cm. long 
% leaves ovate, obtuse or obscurely acuminate, serrate 2.2: t s 
Leaves obovate, roun eu a apex, mostly crenate . Be ila 
2 bovat ad t the apex, tl t 3 
i. B. papyrifera larsh. var. occidentalis (Hook) Sargt. Paper Birch. 
A slender graceful tree rarely reaching a diameter of 60 Cme3; bark bronze 
(chiefly in saplings but occasionally in maturer forms) to chalky-white, 
—s»veeling,roadily disclosing a moss-green or orange colored inner bar beneaths 
“branches slender, chestnvt~ — aot ames wen em tan ere nfs ee gg esse. ‘ 
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