oak galls

found lots of different oak galls (all of them on valley oak, Quercus lobata) this morning while i was out walking with zane.  galls are caused by tiny cynipid wasps.  the wasps lay their eggs on the oak trees' leaves or stems and in doing so trigger a reaction that causes the tree to create a gall around the egg where the larva will then develop.  

here are some links with more photos and information:

http://joycegross.com/galls_ca_oak.php

https://en.wikipedia.org/wiki/Gall_wasp

and here is what zane and i found this morning...

neat.  very.