Photos of the day - "mountain ball" cactus

Pediocactus simpsonii, a small but stunningly beautiful cactus is commonly called "hedgehog" or "pincushion" cactus [those names are also commonly applied to other cacti], but my favorite nickname for it is "mountain ball cactus".  This one has always bloomed in the last few days of May into the first week in June - but this year it is two weeks early.

[I have previously posted images of this particular cactus and called it a "Mammillaria", a closely-related genus.  Mea culpa.]