http://www.theodorepayne.org/plants/plants4oakfungus.htm

There is a random site in CA I found listing some trees. I was unfamiliar with it under that name.

Redbud seems to fit the size description. Not an estate or legacy tree but I like them. Any Ilex family members out there? Or are they on the do not plant list?

Thanks, toronado. I love redbuds, but have never seen one in my area that wasn't small and spindly. Slow growers ? Love Forest Pansy, but see few here. At best, most are small accent trees, I believe.... Like an ornamental plum.

I found a list of resistant species prepared by UC Berkeley. It seems to provide a number of options that could work for you. Maybe compare the list against what you find available at your local better garden center for something that will call out to you and make that statement.
Armillaria resistant trees and shrubs

Hi g.gal...thank you ! I did see that site. Seems the best one., but nothing jumped out that was close to THE one. I won't find a huge boxed tree at a nursery. Will probably have to visit a wholesale place. This one tree I will want to see vs blindly order. I adore liquidambar ...have three in front , and see there is a shorter one called oriental...or close to that. I'm not fond of the spiky balls, tho, and the variety without them is too skinny. Sigh.

Gardengal-
Great idea to post that, but some of the items on it raise eyebrows to me.
Arbutus menziesii are known to be having problems with root rot in the PNW, in garden situations where they receive irrigation. I certainly wouldn't plant one in California in an area already known to have root rot problems. Especially as nursery purchased ones might not have the best genetic heterozygosity.
Since it's highly likely the the most virulent root rot pathogens are coming from Asia...much as it's politically incorrect to recommend a non-native species, I'd recommend something Asian and drought tolerant if I really wanted a trouble-free tree in a part of CA already known to have a problem...and where, as I assume is still the case w/most CA ornamental gardens, there will be some summer irrigation. The Huntington is having to remove all the old native CA Quercus because watering the camellias under them is now causing root rot.

Arbutus menzesii has a lot of problems to be sure, but susceptibility to armilaria is not one of them. The bulk of their problems center around fungal issues (some 19 prevalent ones at last count) including at least 3 more or less lethal cankers. And annosus root rot. And SOD.

I didn't go through the list tree by tree but only reported it for armilaria resistance (I did notice some choices I thought were less than ideal for a SoCal garden). I would never recommend planting a Pacific madrone in a cultivated garden. They have enough trouble staying alive in their native environment, let alone in a garden setting with foo-foo improved soils and regular irrigation. They absolutely hate that. They are almost impossible to find in PNW nurseries for purchase for that reason.

LOL - well, I hope you can forgive me for assuming Armillaria might be one of the "19 prevalent" fungus issues affecting them in cultivated gardens! Sounds like the situation is even more dire than I'd thought.

Yes, it is quite sad. Where I live native madrones are everywhere but it is nearly impossible to find one in good health. Virtually every one is afflicted by some form of leaf spot and/or dieback. Lots of dieback. Now and again you do find one that appears to be thriving but these tend to be located in very close proximity to the beach on the higher rocky bluffs, a situation they prefer. Further inland, even just a few hundred yards, the signs of disease become evident.

But the tough old things respond every spring with new growth. Most are blooming right now and you can see the fresh green growth and a froth of flowers capping the old spotted and dead leaves. Which look a bit like they've been hit with a blow torch.

So, how about the liquidambar orientalis, "Turkish sweet gum," variety? We won't be walking under it a lot, so it's spiky balls won't be a big bother. Besides, I've always felt they are a small price to pay for their beauty. Thoughts, please, and/ or other suggestions. Ty!!