William Bridge Cooke:
An avid collector and much more

© Else Vellinga

Original publication: Mycena News, October 2014

Chances are that you have never heard of William Bridge Cooke—an Ohio-born mycologist who lived from 1908 till 1991. Yet he played a big role in the history of California mycology.

William Bridge Cook

I came across his name over and over again while working on the digitization of the herbarium collections at UC Berkeley. He contributed over 2100 mushroom collections to the herbarium, more than any other collector. Cooke spent the summers of 1936–1941 and again 1946–1947 as custodian of the Shasta Alpine Lodge at the Horse Camp halfway along the route to the peak of Mount Shasta. That meant providing hikers with food, warmth and a shelter, but also ample time to investigate the plants, mushrooms, and other fungi of the area.

And that he did. He made a set of collections of Mount Shasta fungi, which he offered to the University of California, Berkeley. Even more importantly, Cooke discovered that in spring and early summer, certain mushrooms fruited beside the melting snow, coining the term “snowbank fungi” to describe this phenomenon. Melting snow provides the fungi with the dearly needed moisture in what is otherwise a very dry environment: direct sunlight dur­ing the day, and cold—even frost—during the nights. Some of these fungi even fruit in or under the snow, such as Lentinellus montanus. Mycena nivicola pokes its caps through the snow and creates warm little snow-free patches with its fruit body. But most of these fungi fruit where the meltwater drains, and they can fruit by the hundreds. The soil can be black from Donadinia nigrella, one of the spring ascomycetes. On fir branches Pholiota nubigena, formerly known as Nivatogastrium nubigenum, is common. This so-called secotioid fungus—a fungus that does not have exposed gills, but keeps the spores enclosed in the cap—smells strongly of bubble gum with a chemical component. It grows on wood, and is widespread in the western American mountains. Cooke noticed that squirrels sought this fungus out, ate a bit of it, and left the rest on rocks to dry and serve as food when there was nothing better to eat. (That is my interpretation, as I find the smell of this mushroom utterly offensive.)

Lentinellus montanus © Michael Wood

These fungi are still around; the For­est Service has encountered many of these snowbank fungi during the 2011-2013 spring surveys in the Shasta-Trinity National Forest, probably on some of the very same spots as Cooke had seen them 70 years earlier.

This year of extreme drought made me more aware of the uniqueness of the western montane mycoflora, which does not occur anywhere else in the world. Europe’s mountains have their “Schneetälchen” (snow valleys), little depressions in which the snow melts late and where low-dwelling dwarf willows support a specific mycoflora, but not really a spring aspect of the fungal fruiting. I wonder how many more years these specialized fungal habitats will persist under the warming conditions, which impact the snowpack in the mountains.

William Bridge Cooke also gave the giant fuzzy polypore of the Pacific Northwest its species name, nobilissimus. Very fittingly, later mycologists placed it in a genus of its own: Bridgeoporus, named after our protagonist. Bridgeoporus nobilissimus fruits at the base of very old Abies procera and Tsuga heterophylla, where it forms gigantic shelves that Cooke estimated were more than 300 pounds in weight. These form little ecosystems in themselves, harboring yeasts, algae, ferns, and other plants among the fuzzy hairs on the top. Very little is known about the ecology of this species that is now known from a few sites in Washington, Oregon and northern California. We do not know how long it lives in the tree before it forms fruit bodies, nor whether the fungus is harmful to the tree. Do the spores infect new trees or does the fungus spread belowground with its hyphae? The role of the commen­sals of the fruit bodies is also a big unknown. It would be great to know whether the fungus is in fact much more widespread than we now know based on the fruit bodies. We certainly can say that these reproductive parts of the species are indeed vary rare, rendering the species endangered. We do not know how long the habitat in which these old trees grow will persist, and whether younger trees will ever grow old enough to harbor the fruit bodies.

In his ‘real life,’ Cooke worked as a mycologist for the Robert A. Taft Sanitary Engineering Center, part of the U.S. Public Health Service in Cincinnati, and studied fungi in polluted water and sewage until his retirement in 1969. But the impression I get from reading his obituary and viewing his collections today is that he lived to go out and collect mushrooms. Nowadays we would call him an environmentalist, as he did not like to drive, preferring to walk or take buses whenever he could. And one last thing about him: he went to every foray that was held and appeared “colorfully attired in one of his mushroom shirts, carefully crafted by his wife.”

For more information about snowbank fungi and William Bridge Cooke:

Else Vellinga, Ph.D., is interested in mushroom taxonomy and has been studying mushrooms in California and beyond for years. A frequent contributor to Mycena News, she is also fascinated by interactions between fungi and other organisms. In her free time she knits, and knits, and knits!