The Sex Lives of Christmas Trees (Biology - Suitable for Work)

You may not know, but Christmas Trees, known as conifers, are gymnosperms, which means "naked seed" and develop two types of cones:   the male, which produces pollen, and the female with produces the egg.  

The males are about 1/2 inch long, are in clusters and scaly and are usually on the lower branches.   Their pollen is carried by winds in the Spring to other pinecones on other trees and drop off

The females, are what you think of when you think of a pinecone, and usually after scales have opened and the seeds disbursed.

When the female cones are young, they open up their scales slightly and produce a sticky substance to capture the pollen, but they are not fertilized right away.  The pollen remains dormant and fertilization doesn't occur for a year and it is within the second year that fertilization occurs.

Sperm from the pollen fertilize the gametophytes ("egg") at the base of the scales and they gestate there until they ready then the scales on the female cone open to release their winged seeds to be carried with the winds, although there are some species that do not open up until there is higher temperatures.

Via Mentalfloss and Ohio Plants