Tom Volk's Fungus of the Month for October 2001

This month's fungus is Hygrocybe conica,the witch's hat mushroom

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Hygrocybe conicaIn keeping with a Halloween theme, this month's fungus is the witch's hat mushroom, Hygrocybe conica, also known as Hygrophorus conicus (more on the taxonomy later). With its orange color and witch hat shape, this mushroom is a natural for Halloween. This fungus is common this time of year in coniferous and mixed conifer/hardwood woods-- we took this picture of mushrooms collected by Bernadette O'Reilly in a mixed pine and scrub red oak forest a couple weeks ago. At least here in the midwestern USA, the further north you go, the more likely you are to find Hygrocybe and Hygrophorus specimens. Hygrocybe and Hygrophorus species are reportedly mycorrhizal with both hardwoods and conifers, although I've yet to see definitive proof. They certainly are difficult to culture, indicating that there's something (essential nutrients?) missing in "normal" media. melting, here for a 70 kb wav file

You may have learned this species as Hygrophorus conicus, but for many year there Hygrocybe has been segregated from Hygrophorus. I did not believe in this separation until I traveled to the mountains of New Mexico and Colorado in 1997 and saw the wide variety of Hygrophorus species out there-- none looking anything like the brightly colored species we have in the midwest. In the field the distinctions between the genera are pretty clear, with a few exceptions. A third genus Camarophyllus, is also segregated out by some. These genera are placed in the family Hygrophoraceae because of their waxy gills and mycorrhizal habit. My students often have trouble with "waxy." I tell them to think of waxy here as the consistency of soft candle wax, not of hardened cold candles.

trama of Hygrocybe and HygrophorusThese genera, once all placed in the genus Hygrophorus, are now separated from one another on the basis of microscopic characters, primarily the arrangement of the hyphae in the gill trama. The gill trama is the flesh of the gills, underneath the outside layer of basidia and basidiospores. To determine the arrangement of the trama, you should look to see how the hyphae grew out from the center of the mushroom toward the outside. In Hygrocybe the gill trama hyphae are parallel to subparallel. In Hygrophorus the trama is divergent. The arrangement of the trama is considered by most agaricologists to be a very important character at the generic level. In the picture to the left, you can see the parallel trama of Hygrocybe conica and the divergent trama of Hygrophorus russula. The origin of each gill section is to the right, and the end of the gill of each section is to the left. The basidia are borne on the outside of the gills, showing up as a dark, dense area in these sections.

However, lumper that I am, I did not believe the distinction was valid until I went to a foray in 1997 in the mountains of New Mexico and saw many species of Hygrophorus there (we don't have very many of these species in our area). Hygrophorus and Hygrocybe are quite different in stature and overall appearance. Hygrocybe species tend to be more brightly colored and much smaller, although there are some bright white Hygrocybe species bigger than any Hygrophorus I've ever seen. Hygrophorus species tend to have more muted colors and are much larger. If you are a "lumper," you might still consider that all these species belong in a single genus, Hygrophorus. Bill Cibula (now retired from NASA) worked on the carotenoid pigments in these genera many years ago, although little of it is yet published. Someone also needs to work on the DNA of these organisms. Taxonomy is often a matter of opinion anyway.

Hygrocybe psittacina, the parrot mushroomThere are many other species of Hygrocybe, ranging in color from red to yellow to orange to white. To the left is Hygrocybe psittacina, the parrot mushroom, so named because of the green color fading out to yellow as it ages. There are many other species of Hygrocybe that may litter the ground, especially in conifer areas.

Below is Hygrophorus russula, our most common Hygrophorus in the midwestern USA. The epithet names comes from the superficial similarity of its fruiting bodies to those of Russula. Note the more muted coloration compared to the Hygrocybe specimens. You probably can't tell from this picture, but these specimens are ten times larger than any of the Hygrocybe species pictured on this page. However, there certainly are a wide variety of colors and sizes represented in each of the genera. Be on the lookout for them in your area.

Hygrophorus russulaI hope you enjoyed learning something about Hygrocybe conica. And I hope you have a Happy Halloween. Maybe you should incorporate a mushroom into your Halloween costume? I'd love to see a picture if you do. I'll even include it online if you give me permission to do so.

Be sure to see my other Halloween fungus of the month pages

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This page and other pages are © Copyright 2001 by Thomas J. Volk, University of Wisconsin-La Crosse.

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