Sinularia has scerlites but I don’t believe green Nepthea has them.
Ok. If that’s so, my request still stands for anybody that can provide a photo. these scerlites are often very roughly described, but never in great detail nor identified in photos.
My colony doesn’t have any noticeable spikes at the base as far as I know. And I don’t really care which of these 2 species it is. Still, I am super curious to see a photo of this feature.