The Hopkinton Area Land Trust is sponsoring a free mushroom walk on Saturday, Oct. 11, starting at 10 a.m. at the Fruit Street fields. Jonathan Kranz, vice president of the Boston Mycological Club and a Massachusetts Audubon certified field naturalist, will lead this two-hour walk designed to explore the joys and hazards of the fungus among us. Space is limited to 30 people. Registration is available at hopkintonlandtrust.org.