Virtual Nature Trail

Scientific name: Ptychoverpa bohemica
Common name: 
Wrinkled Thimble Cap

(Information for this species page was gathered in part by Julie Flaherty for Biology 220W (Spring 2004) at Penn State New Kensington)

Fruiting body of wrinkled thimble capThe wrinkled thimble cap (Ptychoverpa bohemica) is one of the fungal species referred to as a "false morel" or "brain mushroom." The fruiting body ("mushroom") of this species arises in the spring from an extensive, soil-dwelling mass of white, cottony mycelia. The mushroom has a rounded, wrinkled head that may be flesh colored or reddish brown. This head (which can be 1.5 to 3.5 cm in diameter) sits on a solid, white or cream colored stalk that can be  4 to 10 cm in height. The mushroom's head has a folded convoluted surface that resembles the surface of a mammalian cerebrum. These head convolutions maximize the spore-releasing surface area of the mushroom cap. Each mushroom is capable of releasing several million spores from these very short lived, transient fruiting structures. These mushrooms typically grow in clusters which can be predictably found year after year in the same location. The mushrooms only persist for a few weeks each season with the timing for their emergence being influenced by local site conditions and overall climate patterns. There is a suggestion that global warming is causing these mushrooms to emerge earlier and earlier in the spring season. The ideal conditions for mushroom development are moist soils and warm weather. On our Nature Trail, we observe P. bohemica most typically in mid to late April.

Ptychoverpa bohemica is most often found in or around trees or other large vegetation typically close to streams or on the edges of forested ecosystems. It can be seen in both mixed deciduous forests and coniferous forests throughout the world. Ptychoverpa bohemica is an active decomposer of dead wood. Its soil dwelling mycelia also form mutualistic symbioses with the living roots of a number of species of trees (including American elm, white ash, apple, and tulip poplar). These mycorrhizal fungi benefit the trees by greatly increasing the water and nutrient absorptive surface area of their roots. The fungus in turn gains a variety of energy and nutritional products from its close cellular contacts with the  tree roots. Both tree and fungus may be obligatorily dependent on each other for survival.

The mushrooms of P. bohemica are eaten by a variety of vertebrates (including white tailed deer, gray squirrels, red squirrels, voles, and chipmunks) but contain sufficient levels of toxins  (including monomethyl hydrazine) to discourage their use as a human foodstuff. Monomethyl hydrazine is water soluble and may be leached or boiled out of the P. bohemica mushroom prior to ingestion. Even traces of this toxin, though, are enough to cause severe gastrointestinal disorders.

Ptchoverpa bohemica is often found in great abundance in forested areas that have recently burned. The underground mycelia of this species apparently are stimulated to produced fruiting bodies after a substantial ecosystem fire. As the year's pass, however, and as succession re-establishes the above ground vegetation, the density of P. bohemica mushrooms declines back to near pre-fire levels. The profusion of these mushrooms in burned sites is only observed in ecosystems that previously had a well established population of P. bohemica and there is no indication of preferential colonization of this species into burned areas.  

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