Stinkhorns Are a Show-Stopper in the Fungus Realm

While the vast majority of any given fungus is under the ground and not visible, its fruiting body does appear above ground. “Mushroom” is the name we commonly give to the fruiting body of many fungi. The fungus kingdom has some show-stopping fruiting bodies, but perhaps none are as unforgettable as those in the family Phallaceae, the stinkhorns. Although these fungi are more prevalent in the tropics, several species can be found in New England and they typically poke their heads/fruiting bodies above ground in July, August and September. Closely related to earthstars and coral fungi, stinkhorns are saprophytes, feeding off decaying organic matter, especially wood chip mulch.

Like most fungi, they do not cause disease in plants or animals, but contribute to the breakdown and recycling of dead plant and animal remains into humus, minerals and nutrients that can be utilized by plants.

There is a tremendous variety of shapes and colors associated with the fruiting bodies of different species of stinkhorns. Many are single stalks, some spherical and others latticed. Some resemble a part of the male anatomy, some have “tentacles” and others look like Chinese lanterns or crab claws.

As different looking as the stinkhorn species are, they all share two traits. Stinkhorns all arise from egg-like structures located in damp, decomposing material. Some mycologists refer to them as “witch’s eggs.” They are attached to the ground with thread-like mycelia – the true body of the fungus. The outer layer of the egg (peridium) is white or reddish, with two or three layers. The outermost layer is extremely thin and flexible, while the innermost layer is thicker and gelatinous. You can occasionally see remnants of the peridium on the top of the stinkhorn as well as at its base, where it is referred to as a volva. When the fungus is mature the peridium opens up and the stinkhorn grows rapidly. Within hours, some stinkhorns grow several inches, due to the uptake of water. The cells of many of these fungi are extra-large and divide rapidly, but the fruiting body can be short-lived, wilting and collapsing within 24 hours of appearing.

A second trait which all stinkhorns share is implied by their name ­— they all smell quite putrid, and can be detected even by humans from quite a distance away. There is a reason stinkhorns produce this rotting meat-like odor, and believe it or not, it has to do with reproduction. The smell comes from the slimy, sticky spore mass (gleba) that the fungus produces (often at the tip of a stalk or other structure). It attracts flies and other insects which, after stepping in and consuming some of the mass, become very effective spore dispersal agents. This reproductive strategy for getting spores dispersed is fairly advanced — it is quite similar to the pollination tactics flowering plants came up with millions of years later.

Stinkhorns have attracted attention for several centuries and will probably continue to do so for many more. Pliny the Elder wrote about them in the Natural History, 1st century AD. The first booklet ever written about a specific mushroom was about stinkhorns in Holland, in 1564. They have been connected to witchcraft, disease and the devil — but if you can overlook their smell, a more interesting family of fungi would be hard to find.

Mary Holland is the author of “Naturally Curious: A Photographic Field Guide and Month-by-Month Journey Through the Fields, Woods, and Marshes of New England” and “Milkweed Visitors.”