Quercus x ganderi C.B. Wolf (Q. agrifolia x kelloggii)
For those of you keeping score at home, that's a naturally occurring hybrid of California live oak (a.k.a. coast live oak) and California black oak.
I'm on a quest to find some, now that I am living in coastal California among them.
And for those of you keeping score at home in the same freakish, mega-geek sort of way that I do, Q x ganderi is also a naturally occurring cross between a "species" whose acorns mature in 1 year (agrifolia) and a "species" whose acorns mature in 2 years (kelloggii).
It's a hybrid that's not supposed to happen. But, of course, it does. I once did a spreadsheet with all of the naturally occurring oak hybrids listed in Oaks of North America, looking for instances where a "species" with 1 year maturity acorns crosses with an oak with 2 year maturity acorns. There are several such cases, but nearly all of them are from the Big Bend region of Texas where there is a confusing continuum of scrubby oaks that are considered to be "partly evergreen" and where taxonomists are still arguing about the true maturation time of each "species'" acorns. There are "species" in Big Bend whose native range consists of a few scattered hilltops. Taxonomists early on identified Big Bend as a place where you could find some scrubby oak, call it a species or variety, and slap your name on it (or, as I noted in one case, your girlfriend's name on it), and thus gain botanical immortality for yourself and/or your betrothed.
The exception is Q. x ganderi. It's the only cross between a 1 year and 2 year oak that I have found outside of Big Bend. Which means it goes a long way toward proving my theory that the oaks are truly a single species with thousands of local varieties.
It's also called Quercus x chasei - so once again we see the duel/dueling nomenclature in oaks that means a) two guys identified the same hybrid at different times and different places and gave them different names, b) two guys named two different hybrids/"species" but one guy later decided they are actually the same hybrid/"species," or c) no one knows what they hell they are talking about.
My money's on C.
This is still the best site I have seen for both explaining and mocking the taxonomy of California oaks.
Some sites say if I want to find a Qxganderi/Qxchasei that I'll have to go to San Diego (not exactly a hardship) way to the south of me. Others say they exist in Monterey & Santa Clara Counties, well to the north.
I'm hoping that means they are also nearby.