| What a wonderful mother you are to encourage your son's interests this way. Here's a shot of a saguaro cactus in the Sonora Desert which is in Arizona but also extends into California and Mexico. The saguaros often look like people waving to you as you pass by. The "arms" don't grow until the cactus is about 65 years old. 
As far as California goes, here is our flower, the California Poppy: 
Here's a beautiful book about vegetable gardening which your son would enjoy: |
Here is a link that might be useful: How Groundhog's Garden Grew
| How Groundhog's garden grew is a GREAT book. We got it out from the library, and as an avid gardener I just loved the true to life illustrations. My son will be 6 at the end of the month. Here is what our state looks like right now. 
Believe it or not, we have bluebirds here in the winter, a flock of them. What state are you in? |
Here is a link that might be useful: New York State bird - blue bird
