What kind of camellia is this one? If the blooms' petals are turning brown quickly, it could be camellia petal blight. Not sure about the dark areas in the leaves though. I assume you do not water the leaves?

I appreciate your response. It is an April Dawn Camellia. It definitely gets watered, so I'm certain that is not the problem. Based on what I see and the research I've done, I don't think it is being caused by petal blight - though I still just can't seem to figure out what it is.

How often does it get watered? Once a week or so?

Has the plant suffered any cold and/or wind damage? I don't know what your winter has been like in SoCal, but here in SC, we've had an unusually cold winter. Wind and cold (or even too much sun) can 'burn' flowers and leaves. Is your plant in a sheltered location?

Also- is this the first year you've noticed problems with your plant, or is this an ongoing thing for more than a year?

If you think cold/wind probably isn't the problem, you may want to try to get in touch with someone at the SoCal Camellia Society ( http://socalcamelliasociety.org ) or your county extension agency for local expertise- I'm attaching a link below.

April Dawn is a beautiful cultivar- I hope you're able to figure out how to fix whatever's wrong with your plant.

Here is a link that might be useful: UC cooperative extension offices by county