I've never planted a lawn of it, but I've planted a clump of Carex praegracilis in heavy clay soil with two young 60-pound dogs trampling on it regularly, and I found that it didn't at all mind the long, dry, summers that get much hotter here in the Sacramento Valley than for you in the Bay Area. I've been extremely pleased with it; the only problem I've had with it is that Bermuda grass came up in the middle of it and I had a very difficult time separating them. The sedge wasn't entirely thrilled about having me tear up its roots to extract the Bermuda grass. But after sulking limply for a few months, the sedge did recover and survive.

Carex muskingumensis is the first thing which comes to mind. It's common name is Palm Sedge, and it's a great grass. It'll get to 3'+ and likes the conditions you describe. I can't tell you if it's native, because I don't know where you are.

John Diekelmann's Natural Landscaping with Native Plant Communities has great lists organized by type of forest. The presence of a few oaks could give you a justification to go with the oak-hickory forest community, which is a fascinating group of plants (since the oak-hickory forest covered such a large area, the species that grew/grow in it change from place to place, but certain plants are widespread throughout -- Maianthemum canadense comes to mind). A Sierra Club field guide I have goes even further to divide oak-hickory forest into upper slope (drier, sunnier), mid-slope, and low slope (wetter, shadier) communities. The wild black cherry (Prunus serotina) is identified in one of my books as a common pioneer of post-agricultural land. I don't think it is a major component of any of the mature forests, but it plays a crucial role in the transition from plowed fields (which most of non-Pine Barrens New Jersey was at one time or another) back to forest. The maples, especially red maple, may be indicators of a maple-beech forest, which tends to be moister than an oak-hickory forest. (Of course these designations are generalities -- there are maples in oak-hickory forests and oaks in maple-beech forests, etc., as Elaine was saying -- the scientists need to simplify reality to do their work, but reality is always much more complicated.) Make sure the maples are natives. Acer plantanoides (Norway maple) is an invasive non-native that sends thousands of seeds out every year, and will soon turn a lovely wooded area into a densely shaded monoculture where nothing will grow in the parched soil (from which the zillions of surface feeder roots have extracted every bit of moisture). If your 50% maples are Norway maples, I would ignore them in deciding what kind of forest community to use as your guide. One last thought before I overstay my welcome: one of the best ways to find out what natives are appropriate for your woodland is to find woodlands in your area (state parks, bird sanctuaries, preservation land, bike trails) that have similar characteristics to your property -- how dry/wet is it, how much sun does it get, etc. Bring a field guide or two (make sure the guides identify natives vs. non-natives, or 'aliens') and start figuring out what natives are growing there. This will not only give you ideas about what to plant, but also where to plant (this one likes being on the edge of the trail -- it needs some sun; this one only appears when the trail dips into a lower area -- it like wet legs; this one always seems to cluster around the base of trees; etc.) and what plants look good (i.e., natural) together. It may get you thinking about types of plants and other garden features you hadn't thought about, like club mosses, fallen logs or the look of a vine climbing a tree trunk. Perhaps most importantly, these walks will help you acquire 'forest think', which Elaine described and most of the landscaping books discuss: upper canopy, lower canopy, shrub layer, herbaceous layer. (Rick Darke's The Woodland Garden has some excellent discussion of the 'big picture' aesthetics of woodland gardens, although he doesn't fully take the approach of picking a forest type and planting within that community.) ok, I'll stop (can you tell I love talking about this stuff?) Best of luck, -- wd

I don't know about where to get the seeds you're looking for, but here's an idea... perhaps you can take cuttings from plants that you are desiring to grow. In my neck of the woods, on the back country roads it's easy to find old homesteads. Go poking around and you'll be surprised what you might find. I've gotten some great cuttings that way.