Just for fun:
- ShiftA dial up a 12-sided, fan-filled circle
- AltM split all faces by edges
- CtrlShiftB bevel all vertices, with 'clamp overlap' checked

Edit: ... (I didn't think anyone was going to take this one seriously, it's a bit 'niche' :D) .. This method produces duplicate vertices at the bevel-extremes. To get rid of those, and still have separate petals, follow up with:
Play with the bevel settings to see the various effects. These are the ones illustrated:

- Not a bad idea to have an even number of segments; it makes Grid Fill possible, later, if you want it, and subdivides better.
- 'Shape': 0.5 for a circular arc.
- 'Clamp Overlap' means you can drag the bevel to its limit. (see above for removing the resulting touching vertices)
- 'Superellipse' is the default setting, varying from a circular arc to positive/negative elliptical arcs, according to 'Shape', above.