I have converted the majority of my yard to a CA native garden in the past 3 years.
The trees that are over 20 years old on the property are:1 Coast Live Oak, 1 Crepe Myrtle
Established California native perennials are: buckwheats, toyons, fuchsia, coyote bush, monkey flower, penstemons, mallows, salvias, asters, encelias, morning glory, ceanothus, coffee berry etc.
California native annuals are: Arroyo Lupines, CA poppies, yarrow, Blue eyed grass
There is a small lawn (maybe 100 sq. ft) of Bermuda grass that I am not able to convert to CA native plants per my landlord. There is also a sick Magnolia tree about 10 years old with a partially dry rotted trunk.
There is a Campsis radicans that has been managed into a large shrub, a very old Euonymus shrub the size of a small tree, and a few rosemary bushes. All of these are very old.