Cabbage Palm Morphology

[John Snow]

I'm trying to determine the morphological terms of cabbage palms "boots".  Specifically, I'm referring to the area where the petiole attaches to the main palm trunk and forms an inverted "V". 

What is that "V" called?

Most palms do not have this form, but Cabbage Palm (Sabal palmetto) and Bismarck Palm (Bismarkia nobilis) both have this type of inverted V-shape attachment at the base of the petiole.

Also, most helpful would be an scientific literature studying the effect of cutting into this "V" area causing the "boot" to split.

[Bigfish]

Morphologically speaking, it’s just a leaf base, so I suppose the correct term would be a “split leaf base.”  I am, however, not a botanist!

Cutting into it shouldn’t have any effect on the palm whatsoever, since it’s just dead tissue.