Stu,

Is that leaf from last year or is new (this spring) growth?

I believe these leaves are from this yearthese these are from this year

I live in San Francisco Bay area s

San Jose to be exact. I have a lot of problems with curling leaves.

Stu,
Nice I am familar with the area as my mother lived in Los Altos Hills, I just sold her house this year.
San Jose is on the drier, warm side, so don't think it's mold, might be bacterial/viral. With the fluctuating temps this time of year in SJ, it just might be stress causing the curling. Does the curling stop once July hits?

this is the first time it's happened.I did just transplanted about a month ago

Stu,
If you have a lot of black spots, hit it with a systemic fungicide. If its only a few leaves wait and see if it spreads. The leaf curling is usually associated with stress like fluctuating temps, watering, and transplanting can cause it depending.

It's most likely a very common physiological condition called 'oedema', and plants in containers in the Bay Area would be rather prone to the condition because of the weather.

From one of my other posts: Oedema is a physiological disorder that
can affect all plants. It occurs when the plant takes up more water than it can
rid itself of via the process of transpiration. In afflicted plants,
internal water pressure (turgidity) can become so high that some leaf cells
rupture or the contents of cells leak into inter-cellular spaces in leaf
tissue. Oedema is most often driven by excessive water retention in the soil,
but cool temperatures, high humidity levels, low light conditions, soil compaction, or partial
defoliation can individually or collectively be additional contributors, as can
anything else that slows transpiration. As well, nutritional deficiencies of Ca
and Mg are known contributors to the malady. Symptoms vary by plant, but can
include wet or weepy areas on the foliage, blisters that turn from white or tan
to dark brown or black, then gradually turn corky/ scaly/ ridged, and
wart-like or gall-like bumpy growth.

Al

since you just transplanted it...was ther much root damage? You always have problems with curling leaves and you are in a drier area it seems you need to experiment some more. it looks pretty localized to one leaf so you have time.

Try letting it dry out If it actually is too wet. I would also treat with a 3 in 1 type of product to reduce any insect related leaf deformation and disease potential.