62 ; BETULACEAE, 
OstryA. Hop Hornbeam. 
Deciduous small trees with scaly bark: somewhat reddish hard 
wood with minute diffused ducts and fine medullary rays; slender 
somewhat zig-zag terete twigs; roundish homogeneous pale pith; 
alternate 2-ranked somewhat raised small crescent-shaped leaf 
scars with 3 bundle-traces; narrow stipule-scars; elongated ovoid 
moderate solitary sessile buds with several spirally placed finely 
ridged scales, the end bud lacking; simple serrate petioled mod- 
erate leaves; inconspicuous monoecious apetalous flowers in small 
catkins; and small seed-like fruits, each subtended by a larger thin 
scale, aggregated in a hop-like cluster. 
Twigs from villous and glandular, glabrescent. Q. virginaza. 
CARPINUS. Hornbeam. Blue Beech. 
Deciduous small trees with fluted trunks; smooth gray bark; 
pale hard wood with minute diffused ducts and extremely fine 
medullary rays; slender zig-zag terete twigs; rather round homo- 
geneous pale pith; alternate 2-ranked low small crescent-shaped 
leaf-scars with 3 bundle-traces; narrow stipule-scars; elongated- 
ovoid rather small solitary sessile buds with several spirally 
placed smooth scales, the end bud lacking ; simple doubly ser- 
rate petioled moderate leaves; inconspicuous monoecious apetal- 
ous flowers in small catkins; and small ribbed seed-like fruits,. 
each subtended by a hastate bract. 
1. Buds small (3 mm.), dark, for a time hairy. C. caroliniana. 
Buds large (5 mm.), light brown, glabrous. 2. 
2. Tree round-topped. 3. 
Tree conical. C. Betulus pyramidalis. 
3. Leaves green. 4. 
Leaves for a time purple. C. Betulus purpurea. 
4, Leaves merely toothed. C. Betulus. 
Leaves cut or lobed. C. Betulus incisa. 
BETULA, Birch. 
Deciduous trees or occasionally shrubs often with papery- 
flaking or white bark with transversely elongated lenticels; pale 
or reddish often hard wood with minute diffused ducts and very 
