That sort of looks like sunburn in the middle, where the leaf appears to be dry. Though it seems odd it would be getting sunburn in December. Maybe someone else will see this and give advice.

You don't say how much water it's been getting. It appears to be in a container. I'm not sure what's causing the drying. I would guess it's a lack of water.

That plant, though, sure doesn't look like a Cavendish to me; more like a Maurelii.

It is in the ground and the soil seems sufficiently moist. I have a new leaf coming up now so I will check for consistency.

It was sold as a Dwarf Cavendish, but you never know with these nurseries... It is however consistent with a dwarf, as it has not increased in height (at 4'), while it has gotten thicker and put out more foliage. My ice cream planted at the same time, has increased 30% in height.

Now, as I said before, the problem could be from lack of proper water. It could be from numerous other causes. An insect may have crawled down in the cigar leaf, as it was emerging. It could also be from overwatering, or cold damage. (although I see from my Sunset book that you are somewhere is southern California) that would not be likely. The reason that I said it looked more like a Maurelii, is shown in the attached picture.

I will also send a picture of a Dwarf Cavendish, but it will have to be in a subsequent post, as I don't know how to send multiple images on this site.

Here is a link that might be useful: Maurelii

Thanks John. I do have a earwig problem here, so maybe it was an insect. Just seemed very unusual that I was unable to find a relevant example anywhere online.

I've had a couple leaves push up on my musa's like that. Not sure the cause but it doesn't happen on every leaf.