Specimen of the Month: Stinkhorns

Fungi are more closely related to animals than they are to plants. At any rate, some seem more like alien structures. These amazing organisms cover most of our planet – and even in our little corner of the Northwoods, likely thousands of species blanket the forest floors and adorn the trees. Among the great variety of colors, sizes, and forms of these many species, the mere appearance of a stinkhorn is enough to capture anyone's attention. 

Netted stinkhorn (Phallus duplicatus) grows out
from its gelatinous volva.

I first observed a netted stinkhorn (Phallus duplicatus) while my adventurous father visited this one autumn. We had crossed the leaf-littered blacktop that met my driveway one October afternoon to walk to undulating trails through the surrounding forest. Many of my favorite edible fungi grow there at that time – black trumpets, resinous polypores, and various orange chanterelles. Just as we passed the road, a flash of white caught my eye. As I glanced, I was certain that it had been a damp tissue, recklessly disposed of along the roadside. My attention was then quickly drawn to the opposite direction as my father called out about a cluster of mushrooms perfect for eating. 

These fruiting bodies of yellowfoot chanterelle mushrooms
 glow a brilliant orange in autumn light and make a tasty meal.

We eventually made our way back to that spot, baskets full of foraged food. I again saw that flash of white and this time drew closer to investigate. What a sight – and smell! A putrid mushroom unlike any I had before encountered emanated from a slimy, egg-like sac. Its white veil, which had originally caught my attention, hung around the stalk like a delicate doily. I was so amazed by the mushroom that I returned to collect it the next day and preserve it as a specimen for the Museum. From then on, I continued to seek out more information on this new species I had experienced. 

The intricate veil of the netted stinkhorn captures
people's attention, while the putrid gleba on the cap
(bottom left corner) attracts flies. 

I quickly reached out to a fungus expert from our area, Tavis Lynch, who confirmed that what I found was Phallus duplicatus. This is one of a number of stinkhorn species growing around the world – each more odd than the other. Fruiting bodies of these fungi begin inside a gelatinous membrane of an egg-like volva. I learned that if found at this stage, the immature mushroom can be carefully gathered and coaxed to grow indoors. In the case of a netted stinkhorn, a  spongy stem ("stipe") later emerges to support a chambered cap. Covering the cap is a slimy substance called a "gleba." Much like the many plants, who develop specific flower structures to entice their preferred insect pollinators, this fungus produces a carrion-scented gleba to attract flies. In landing on the gleba, flies unknowingly help to spread the enclosed spores to help the species reproduce. 

Unfortunately for me, the scent of this mushroom's gleba was far from appealing. I transported it to the Museum in a sealed yogurt container, but even that didn't help to trap the scent during the fifteen minute ride from home. Once I removed the cover in my back work space, the odor worsened. I worked quickly to cover the mushroom in its preservative solution – three parts ethanol to one part water – and sealed it off for good. 

The egg-like volva (below) separated from the
spongy stalk of this stinkhorn before preservation.
In liquid, the gleba separates to reveal the
honeycomb structure of its cap.

Surrounded by the alcohol solution in a glass jar, I hope that the remains of this fascinating fungus will capture the attention of others and inspire them to explore the amazing mushrooms growing in our area. Soon the season on plenty will end and I'll start dreaming towards next year.