Clicking on Petal in the Flower Parts drop-down menu will add it to the Flower Layers list.

When Petal is highlighted in this list, the following attributes will all be accessible.

Main tab

Petal Type

Set as Standard, by default.

The alternative is Cone, which has some different parameter options.

The two Petal Type settings of Standard and Cone.

Main tab - Standard petal settings

Seed

Gives a different, random arrangement, based on the other values set.

Count

This can be increased or decreased.

Count set at 8 on the left and 20 on the right.

Radius