Two Cases of Unusual Development of Fruit Bodies

Those who are familiar with fleshy Agaricales know that the geotropic response which results in an orientation of pores, gills, or other spore bearing surfaces perpendicular to the surface of the earth, sometimes goes awry, especially if fruit bodies are diseased or mechanically injured. Fruit bodies produced in unnatural environments, as on agar cultures or on wood in jars, sometimes exhibit a capricious orientation of pores or gills, indicating that forces other than gravity are involved in such orientation. Following will be described two interesting cases of such nongeotropic development. The first case involves an agaric (Russula sp., tentatively identified as R. atropurpurea Peck) observed at Itasca Park, Minnesota, in September, 1937. More than a decade before that time several pits about 5 feet square and 4 to 5 feet deep had been dug for experimental purposes in the level ground in a Jack pine stand. During a rainy spell in September, 1937, when fleshy fungi were rather abundant, the writer observed 2 fruit bodies of this species of Russula growing out of the vertical walls of one of the pits. One appeared about a foot from the surface of the ground, the second about 2 feet from the surface and on an adjoining wall. The stem of each, although short, extended straight out from the vertical wall, no upward curve being visible. The cap in each case was parellel to the wall. The gills were normal, although the free edges of those on the upper side bent over as they lost their turgidity with age, as can be seen in figure 1. In other words, the fruit bodies were oriented in the same way to the perpendicular surface from which they grew, as fruit bodies growing on approximately