It comes from Haapsalu region of Estonia where traditionally waterlily pattern would be used for lace shawls.
I have got more potholders and washcloths than any sane person could reasonably want. But I think – as small knitting projects go – they are great to try out shaping ideas and techniques And the techniques that are used here are short rows, slipping stitches and weaving in yarn while knitting. Other than that you only need to be able to do garter stitch. The first two big petals are shaped in a way that they have a small “cut out” at the left side. The middle petal is symmetrical, and the last two big petals are shape mirror-inverted to the first two. Between two big petals there is a small petal. This is shown below.