urbpan | Rare urban mushrooms

Mushrooms and other fungi are common in urban environments, but like (for example) urban birds, while there may be many individual organisms, there is reduced biodiversity. The kind of fungi that are common in cities are those that feed on wood chips on landscaping, and on dead wood. This latter category may be seen only infrequently, since dead wood is usually cleared away rather than left to rot (grow fungi) in the city.

Another category of fungi are those that are mycorrhyzal. These are fungi that grow in association with living plant roots, in a form of mutualism. The kind of mycorrhyzal fungi that produce mushrooms grow amongst tree roots. The fungus takes some of the tree's photosynthesis-produced food, and in return helps the tree absorb water and other nutrients. It may take many years for this relationship to become established, and to result in mushrooms. The average lifespan of an urban tree is less than ten years, so most trees in the city will not have mycorrhyzal fungi in their midst.

Fortunately, the Riverway in Boston and Brookline is lined with hundred-year old beech and oak trees, planted when Fredrick Olmsted designed the park in the late 19th century. This week we've seen mycorrhyzal mushrooms from the Amanita, Bolete, Lactarius and Russula groups appear. Many of them are colorful and beautiful. Photographs are by