Example of how to create needles for conifer plants

You can create leaves using the Standard leaves node. Just select the rectangle and set the Length/Width proportion to be equal to 15, for example. Besides, you need to set the path length, to make it equal approximately to the length of a needle and specify the same value for the Steps in the Path node. The plant will be calculated quickly, and the needles will have the least number of faces.

An example:

Result: