Getting rid of overlap

Create the petal.

 

 

 

Set the point of origin for the rotation by clicking on the rotate tool in the toolbar to make it active, then holding the option/alt key as you click the point you want the petal copies to rotate around. Double click the rotate tool and set the rotation angle you wish. This one is set to 20°. Click Copy.

Use command/control +D to add as many petals as you want. There were 16 added here.
As you can see the last petal is on top instead of tucked under the first one.

 

Select the last petal.

 

 

 

 

 

 

 

Remove the fill from it so you can see behind it.

 

 

 

 

Select the knife tool, and draw around the area you want to hide.

 

 

 

Hit the delete button to get rid of the extra piece.

 

 

 

Add the fill back again. Unless you are absolutely exact in drawing with the knife you may need to use the arrow keys to nudge the piece of petal snugly against the one to it's left.