Why Does My Bismark Palm Doesn’t Have Seeds.

Question

It’s an eighteen year old palm and around 20 feet high.

Answer 1

There are separate male and female palms. You will need both in order to obtain seeds. The female is more important, since any males in the area can pollinate the female, which will bear the fruit.

https://www.gardeningknowhow.com/ornamental/trees/bismarck-palm/growing-bismarck-palms.htm