Petal puzzles are an interesting form of crossword
In each petal puzzle, all the answers are the same length. The grid consists of two sets of crisscrossing arcs, and the somewhat irregular diamond-shaped spaces between these arcs are the grid cells. These cells line up in two different directions along the different sets of arcs, usually described as traveling clockwise and counterclockwise around the hole in the center.
Usually the outside cells are numbered clockwise, starting at the top of the grid, and there are somewhere between 16 and 24 of these numbers. Clues are provided for each numbered clockwise and counterclockwise entry.
The grid is topologically equivalent to a diagonal strip of constant width in a conventional crossword grid which wraps around at the ends.