Interesting mushroom, Rounded Earthstar and ramblings about the dearth of acorns

I spotted these unique looking mushrooms growing under a Colorado Blue Spruce while on the dog walk. Last year I noticed a dry husk of the same mushroom on the sidewalk where the current crop is growing. At first I thought the dry husk was some kind of dry flower like Woodrose, Merremia tuberosa but it was spongy and leathery rather than brittle like the woodrose so I thought it must be some kind of fungus.

I looked it up in my Audubon mushroom guide and found it is Geastrum saccatum the Rounded earthstar. Here's a nice website on Geastrum saccatum. It's supposed to be a common mushroom but I have only seen it once, twice now under this particular blue spruce. The fruiting body resembles an acorn - which speaking of is very scarce around these parts this year. We had a bumper crop of acorns 2 years ago and a lot last year too but nada this year, not a single one to be found on any oak tree. I heard an NPR interview with a Northeast naturalist and she also mentioned the scarcity of acorns this year. I wonder what's up??