Colorful fungi: Stinkhorn emits foul odor

As the warm weather becomes progressively warmer, there are certain occurrences which become obvious. For the home landscapes of Tallahassee residents the most noticeable is the grass needs to be mowed frequently, and as a result the mower blade will need to be sharpened several times over the course 2019’s summer.

And in case it has slipped anyone notice, the mosquitoes are becoming more active with the many breeding sites. Home owners in Leon County and north Florida should be draining the excess moisture from anything holding untreated water more than a day or two.

Another observation is the addition of colorful blotches of suddenly appearing at ground level which are not flowers. A local mushroom species is taking advantage of the plentiful moisture to establish itself in new areas.

Clathrus columnatus, the scientific name for the column stinkhorn, is a north Florida native which is common to many gulf coast locales. This colorful fungus has also been known by the common name “dead man’s fingers,” among other labels.

The short lived above ground structure is usually two to six inches high at maturity.  This area is known as the fruiting body and produces spores which are the basis for the next generation.

Two to five hollow columns or fingers project upwards above the soil or mulch. Coloration of the fruiting body can range from pink to red, and occasionally orange.
The inner surfaces of the column are covered with stinkhorn slime and spores, and which produces an especially repulsive stench to humans. This foul odor is useful though, attracting an assortment of flies and other insects which track through it.

A small amount of the brownish slime and spores attaches to the insect’s body.  It is then carried by these discerning visitors to other bug enticing spots, usually of equal or greater offensiveness to people. Spores are deposited as the slime mixture is rubbed off as the insects brush against surfaces. 

Decaying woody debris is a favorable environment for the column stinkhorn to germinate.  As the wood rots bacterial activity makes necessary nutrients available to this mushroom.

Other areas satisfactory for development include lawns, gardens, flower beds and disturbed soils. All contain bits and pieces of decomposing wood and bark.
Occasionally, column stinkhorns can be seen growing directly out of stumps and living trees. Presence on a living tree is a good indication the tree has serious health issues and may soon die.

This fungi starts out as a partially covered growth called a volva. The portion above and below the soils surface has the general appearance of a hen’s egg and is bright white.   
The term volva is applied in the technical study of mushrooms, and used to describe a cup-like structure at the base of the fungus. It is one of the visible features used to precisely identify specific species. 

The recent wet weather in Leon County combined with local sandy soils and available nutrients create ideal growing conditions. While rarely notices during initial stages of growth, they are quickly spotted at or near maturity.

There are other stinkhorn mushrooms in north Florida, but they are not as common. In addition to North America, member of this fungi family with a fetid aroma can be found in Europe, Asia, South America and Australia.

If hidden by tall grass, the person handling the mower will quickly realize they have encountered a local stinkhorn.  At least they do not dull the mower blade.
To learn more about north Florida’s mushrooms, contact your UF/IFAS Wakulla Extension Office at 850-926-3931 or http://wakulla.ifas.ufl.edu/
 

Les Harrison is the UF/IFAS Wakulla County Extension Director and Agriculture and Natural Resources Agent.