both walls are longitudinally folded, resulting in stellate transverse section

knowledge base : exist
structure : morphological structure
Cup shapes : isn't included in the term
Shape of cup bulges : Both walls show folds
Type of folds affecting both walls : Longitudinal folds (stellate transverse section)
Habitus : isn't included in the term
Central Cavity (or internal if one wall) : isn't included in the term
Thorny corolla : isn't included in the term
Chambers : isn't included in the term
Other aquiferous unit : isn't included in the term