FROM BALES OF ORGANIC WHEAT STRAW burst forth these fine-fluted mushrooms, grown inside a greenhouse at Newburyport’s Shady Oaks Organics. The year-old cultivator, formed out of three upstarts, expanded this spring from a basement operation to a 23,000-square-foot space. There, the founders are spawning hard-to-find varieties of shiitake and oyster mushrooms — golden, Italian, and Po Hu, which don’t grow in the New England wild — giving Boston chefs an organic, year-round mycological treat. At Menton, you’ll find Shady Oaks oyster mushrooms pickled alongside scallops and sea-urchin ravioli. The company also sells them by the bag, so you can experiment on your own with their nuanced nuttiness.

$4–$5 for 100 grams; available this summer at Boston City Hall Farmers’ Market, 100 Cambridge St., Boston; shadyoaksorganics.com.