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Tuesday, January 24, 2012

Quercus ilex - Holly Oak

Holly Oak is a nice oak, just good old nice, cant say it ever brings out a "wow" like some of the oaks. It is a very popular oak tree and commonly planted. Medium growing evergreen (non-native oak but very common) tree 30 - 40' tall and about the same wide. The holly oak forms a dense, oval to rounded crown. This is an old specimen in England.


This is more like what we see here, this one is at San Lorenzo Park by the pond. Obviously a mistake, as all the other oaks in the park a Cork Oaks, and nice ones at that. In Pacific Coast Trees by McMinn and Maino, the authors suggest that these two trees are commonly confused.



Leaves are evergreen, simple, alternate, oval to ovate to lanceolate shaped, 1-3" long, margins entire or lightly spinose and slightly rolled over, dark green upper surface, white on the lower surface. Often with a slightly pointed tip. Variable like so many oaks. Younger more vigorous leaves tend to have more teeth.






Male flowers are in catkins, elongating in the spring, females are borne singly a bit further back from the ends.



Fruit of course is an acorn. The cap or cup is large and covers much of the acorn. Acorn is 3/4" to  about 1" long, can be brown to black when mature. Seems there is a second botanical variety that has almost black fruit. 



Younger acorns.



Stems are grayish or copper colored, hairy, and often take on a dark color as seen in this image.





Bark is checked in small pieces.


Older trunks are way cool.


Misidentification: Look for the white undersides of the leaves. Also, something caused the stems and older leaves to look like they have sooty mold but there does not seem to be any insects.
Q. suber also has a light colored leaf underside but the leaves are smaller, more blue and the bark is key.

Location: San Lorenzo Park by the pond is a nice specimen and while you are there look at the cork oaks.