While mushroom walks have become popular among epicures, true fungiphiles like Ristich look for all species, not just edibles, and ooh and aah over minutiae and strange growths on rotting wood that look nothing like a typical capped mushroom. To them, a mushroom foray is a hunt for treasures with Latin names like Leucocoprinus luteus (yellow parasol), Suillus americanus (white pine bolete), and Trametes versicolor (turkey tail).
''I'm not out only for a mushroom walk, I'm out for a walk of wonderment," said Ristich, who has a doctorate in entomology from Cornell University. ''I look at everything. You must look above, and below, and on all sides."
In New England, wild mushroom collecting begins in May with short-lived morels like Morchella esculenta (yellow morel) and Morchella elata (black morel), prized as delicacies. But the peak season traditionally runs mid-July through October for most of the approximately 2,000 species cataloged in the area. The best time to go is four to 10 days after significant rain.
In Maine, Ristich said, picking has been erratic this season due to lengthy dry spells.
While it's impossible to know how many hunters gather mushrooms in the woods, either singularly or in groups, a spokesman at the Northeast Mycological Federation Inc., an organization consisting of 18 clubs that have sprouted up from Canada to Pennsylvania, said affiliated groups average 140 members.
Portobello, shiitake, and other cultivated varieties found in restaurants and on grocery store shelves have whetted consumers' appetites, collectors say, though less than a quarter of a typical harvest on leisurely walks like the one led by Ristich is edible.
''My primary interest is in finding stuff I can put in the pan," said 69-year-old Anne Rugh of Portland, a Persian rug dealer along for the outing, ''but I can't help being drawn into the rest of it."
Affectionately nicknamed the ''Mushroom Guru" (or sometimes the ''Guru of Sligo Road," after the street on which he lives), Ristich has achieved ''mycogod status" among an elite subgroup of hard-core mushroom aficionados.
