The part found on a male plant that is essential for fertilization of a female plant is pollen.

Here's a breakdown:

* Male plants produce pollen, which contains the male gametes (sperm).

* Female plants have structures called pistils, which contain the female gametes (eggs).

* Pollination is the process where pollen from the male plant is transferred to the female plant's pistil.

* Fertilization occurs when the pollen grain reaches the ovule (containing the egg) inside the pistil. This results in the development of seeds.

So, pollen is the key ingredient that connects male and female plants in the reproductive process.