Thursday, August 8, 2013

Lithocarpus densiflorus - Tan Bark Oak

The tan bark oak is not a real oak, as you can see by the genus name, and yet it has acorns. I have not always understood this but I am not an expert taxonomist. This beautiful native evergreen tree grows pretty tall, 40-90' depending on its location. In the shade can be very narrow but grown in the sun can have a rounded dense crown. I have noticed all those growing in a typical forested setting have a very straight unbranched trunk. The lateral branches have a self shedding habit making for a tall straight trunk.  A tree in Monterey county reported to be over 200 feet tall with a trunk over 4.5 feet.

This is the tree at my neighbors house, its the one in the middle.




These are in Nicene Marks growing as strong single trunks.



The evergreen leaves are alternate, simple, 3-6" long, maybe 1.5" wide, oblong to elliptic with sharply serrated margins that are often revoluted as well. Generally dark green but also bluish green on the upper surface while the lower surface is covered with gold tomemtum. The petioles and young stems are also covered with the same hair. Leaves last 3-4 years before falling.





Stems are stout and round, covered with dense pubescence for the first or second year, reddish brown.



Flowers in long upright spikes emerging late June and into late July 2-5" long. Females in same inflorescence as the males but at the base. Which is why they are not in the genus Quercus. Flowers resemble that of a Chestnut. Read somewhere that it is actually believed to be a cross between an oak and a chestnut. 



Acorn, cup shaggy when young, 1-1.5" long with burry caps and a short thick stalk.  Used extensively by native americans. Mature in 18 months.



Bark is really pretty nice. Gray on the surface with deep furrows of black. Add in the really cool looking branch collars and the self shedding habit and you can see why.






Arthur Lee Jacobson mentions a Cutleaf Tanbark oak, Lithocarpus densiflorus f. attenuato-dentatus.
New name alert: Notholithocarpus densiflorus


Misidentification:
An oak because of the acorns and leaves. I cant think of many oaks with really heavy pubescence on the stems and leaf undersides. They also bloom mid July.

Location:
Aptos
406 Simple Ave, along with many other native trees, including Sequoia, Aesculus, Arbutus, Quercus, and shrubs Toyon, Filberts, Arctostaphylos.