The Farther East River

Mushrooms in Manhattan

Q. At a construction site on West End Avenue at 70th Street, mushrooms (yes, mushrooms!) are growing underneath the construction fence. What kind of soil is necessary for mushrooms to grow?

A. Ah, resilient nature. Roy Halling, curator of mycology at the New York Botanical Garden, said in an e-mail message that he would not expect to encounter mushrooms in a construction site because the soil is mostly mineral. The mushroom fungus requires living or dead organic material to live: for instance, compost, dead wood, manured soil and wood chips. “However,” he added, “at the edge, where some organic material has been pushed aside, it does happen. Just exactly which ones those might be — it is impossible to say.” And not even an expert can tell, sight unseen, whether they are edible, so don’t sample them.