Yule, Winter Solstice, usually falls upon December 21st in the Northern Hemisphere, (but occasionally on the 20th or the 22nd), marks the first day of Winter, and the longest night of the year.

Many traditions around the world have their most elaborate festivals around this time of year, including Christmas and Hanukkah, as well as Yaldā, Koliada, Malkh, Mōdraniht, Sol Invictus, and Saturnalia.

Burning an oak Yule log, and decorating an evergreen tree with a star, lights, holly, pine cones, and handmade ornaments are central to this holiday.

The amanita muscaria mushroom has an ectomycorrhizal symbiosis with many trees, including pine, spruce, fir, birch, and cedar, as well as a special relationship with reindeer, which go to great lengths to seek them out.