Hi
have seen this type of growth on rare occasions.. Mostly in Bo gardens. Wonder what causes it?? have also seen it in a few palms . Sure makes them vulnerable to wind damage.. gary

I seems to be intiated by some kind of trama to the end of the rhizome. Whether from impact, drought, or infection such as rhizoctinia. The fern was well protected from wind. I had be watching a two headed Phoenix dactylifera (sp) growing near the freeway until it was decapitated by hurricane Ike.