The original E. mammillaris was known to occur from the Riversdale district in the west to the Oudtshoorn area in the east. The plants growing there look like the ones in the first 3 pictures.
Pictures 4 and 5 show plants from near Port Elizabeth in the Eastern Cape. They represent what used to be called E. fimbriata, with rather narrower and more sinuous stems. This habit is an adaptation to the growing conditions there: a dense cover of bush or grass as opposed to the open habitats in the west.
