F'AGACEAE. 29 
QuERCUS. Oak. 
(Family Fagaceae). 
Trees or rarely shrubs: mostly 
deciduous, though the dried leaves 
often persist. Twigs moderate or 
slender, fluted: pith moderate, 
star-shaped in section, continuous. 
Buds solitary or sometimes col- 
laterally multiple, sessile, globose 
or ovoid to conical, sometimes an- 
gled, clustered toward the tip, 
with numerous 5-ranked scales. 
Leaf-scars alternate, moderate or 
rather small, half-round, some- 
what elevated: bundle-traces near- 
ly a dozen, scattered or partly in 
a more or less evident ellipse: 
stipule-scars small. 
The Danish botanist Oersted 
was very keen in discerning the 
differences that oak buds show, 
and Willkomm’s differentiation of 
the two oaks of northern Europe 
that have been confused under the name Quercus Robur is as 
clean-cut when this character only is used as it is when their 
fruits show the distinction because of which one has been 
called variety pedunculata and the other variety sessiliflora. 
No differences between the common red oak (Q. rubra) and 
Schneck’s oak (Q. Schneckii), or between this and the Texan 
oak (Q. texana), are more obvious to a close observer than 
those between their winter buds, but comparisons need to be 
made between developed buds on mature branches. 
1. Black oaks: fruit maturing the second year. 2. 
White oaks: fruit maturing the first year. 16. 
