I'm assuming your 24" x 32" (" = inch) space is really 24' x 32' (' = feet)?

A lovely California native shrub with a woodland look is Coffeeberry (Rhamnus californica aka Frangula californica).

You could also add another beautiful native shrub, Ceonothus 'Ray Hartman' and limb it up into a petite tree. The blue flowers in springtime are gorgeous.

Toyon, Heteromeles arbutifolia, is another native shub that can be limbed up into a petite tree, but shrub or tree, it has a very woodland look.

Once established, these plants can do fine on very limited irrigation. Fall is the best time to plant California natives. Usually the first summer after planting is the time when the plant may need some supplemental irrigation, and after that can manage on rainfall alone.

Take a drive out to the Rancho Santa Ana botanical garden in Claremont and see what a native California woodland can look like--very beautiful!

You haven't mentioned if you are interested in using California native plants or not. But if you want to consider it, go to the theodorepayne.org website to see the variety and beauty of California native plants. Many are appropriate for a woodlands habitat. And typically, after they are established (as hoovb said), they will need less water than the types of plants you buy at the local nursery or Lowe's etc. The Theodore Payne Foundation sells tons of plants and it's just down the freeway from Pasadena.

If you would like to study what would work well from the comfort of your home, check your library for a book by Bob Perry called "Landscape Plants for Western Regions". Bob Perry is a professor at Cal State Pomona and the book is wonderfully illustrated. Al

Do you have neighboring large trees close by? Anything to give the feeling that yours is a *clearing* in the woodland? Does the idea of a woodland tie in visually with your house and the rest of your property? The feeling of a woodland is not only in which plants you choose, but in how you grow them. You don't want anything manicured, I think leaf litter is the best mulch. Definitely some large type shrubs that can be trimmed into open tree shape, multi-trunk. I think the grasses are very important, obviously not the showy ones. I use the pennisetum that everyone tells you not to plant because it's invasive...lol...It's already here and I don't find it to be a problem weeding out any unwanted seedlings (actually, I use them). There is the sterile form that you may find appropriate. My property is 'woodsy', but I have a larger space to work with and eucalyptus trees. Beneath the eucs along the drive there are the pennisetums and cistus skanbergii. There are a couple of the pennisetum setaceum rubrum also and maybe three salvia Indigo Spires thrown into the mix to give a jolt of color. They require more water than the rest and will come out, but there are the native salvias that would work well in this combo also. Salvia brandegei for upright, or one of the salvia clevelandii, salvia 'Bee's Bliss' for groundcover, or salvia repens....these are all extremely drought tolerant. I also like erigeron / Santa Barbara Daisy once it is allowed to become what most would consider 'overgrown'. It mounds and tumbles then. So many plants you can use, but important to tie this all together with the landscaping of the rest of your property.

Pomegranate and Elderberry are small drought tolerant trees. Figs are very drought tolerant and hardy, but can have an invasive root network, so consider that (because it may be difficult to plant things under the tree). Pakistan Mulberry and Fruiting Quince can also be fairly drought tolerant. Maybe a Spanish Cork Oak? There's also Arbutus, which is a low maintenance ornamental and has semi-edible little fruits.

Have you heard of Spanish Foxglove? That may be an option. There are also colorful wildflower seeds you could plant. The California wild rose is drought tolerant and can add an attractive wilderness look.

Berkeley sedge is not a native, but it does (too) well in my yard and might be a good clumping grass for you.

I second Theodore Payne. It's about ten minutes from where you are and they have a nice selection of CA natives and very helpful volunteers.