This evening I found s few of these fungi growing in a compost pile:
Here is a view of the bottom of one of the smaller ones:
I looked around for an identification in mushroom guides and on the internet. The best match I could find is Calvatia rubroflava, also known as Orange-staining Puffball. (If anyone has a better identification, please leave a comment.) The linked site notes that although the mushroom is edible, "it is distinctly unpalatable and the odor of the mature mushroom is very disagreeable." The smell of this one certainly matches the description. I could smell it from several feet away!