I don't know the answer but I remember seeing this on curly parsley in grocery stores. Some of the leaves were "extra curly" and they felt stiffer. The texture was not as enjoyable when eaten raw.

Looks fine'

Parsley is grown from seed and therefore you can get a certain amount of variation in the foliage of different plants.

Thank you all! I would alternate seed and plant but this time this one looked funky. I'll taste it in a few minutes and hopefully its not nasty.