Q:

Can Oyster mushrooms grow on a Yucca tree?

I am not certain of the exact species of this Yucca (Maybe Yucca Guatemalensis?)
But there are several of these trees growing in the front yards of several homes in a co-workers neighborhood in the San Francisco peninsula area.
Recently, mushrooms started growing on the trunk near the base of a few of these yuccas, one of which is now clearly dead & the one that the mushroom pictured below was harvested from looks to be on the way out too. I would guess that the yuccas were already sick & dying if these are indeed oysters, as they are a  saprotrophic mushroom.
I had never heard of oyster mushrooms growing on a yucca, nor can I find any mention of this happening through several google searches, so I am not quite sure what to think of this apparent oyster mushroom. It is fairly large (as big as my hand) and I find it a bit odd how broadly fussed together the caps are at the base.

This is one of the mushrooms, cut from the yucca next to the trunk.

A:

They certainly do look like Oyster's. Without seeing the stem it's hard to know for sure. A white spore print is also a good indication. I've seen many Oyster's that split off like that as well.
I did find one forum that addresses whether or not they can grow on Yukka. It seems that the major consensus is yes. https://www.shroomery.org/forums/showflat.php/Number/12812751

