Somewhere in Southern California Stu Pickell, mushroom hunter, is elbow-deep in dirt.

Lying flat on the ground in a narrow canyon under a towering bigcone Douglas fir, he paws up handfuls of gently fragrant humus. Occasionally he sniffs it, searching for the scent of his quarry: a unique type of black truffle that hasn’t ever been observed before in drought-parched Southern California. This tiny pocket of trees in the Santa Ana Mountains could be its ideal habitat, he thinks—and now could be the best time ever to actually find it.

Normally at this time of year, Pickell might be hunting for chanterelles in Mendocino or searching for slime molds in Alaska. But today, the fungi aficionado and photographer is searching just a few minutes