The form of Latin S arises from Greek Σ by dropping 1 out with the 4 strokes of that letter. The (angular) S-form made up of a few strokes existed like a variant of the four-stroke letter Σ by now inside the epigraphy of Western Greek alphabets, as well as https://budnakedflower87516.amoblog.com/a-review-of-bud-naked-mushrooms-53255147