Temporally Structured Fruiting of Gregarious Russula Species in the Temperate Fagaceae Stands

Although it is well known that there are temporal patterns of annual fruit body production, accurate descriptions of the patterns have not yet been available due to the short‐lived trait of the fruit body. In the present study, a 4‐year (three times a week) observation of fruit body production in Russula densifolia Gillet occurred under a Fagaceae stand revealed consistent two‐step fruiting in September, i.e., the smaller fruit body appeared first, followed by a larger basidiocarp, usually within a 1‐day interval. The production of smaller fruit bodies showed the interannual variation over a 4‐year observation period, while the larger ones remained rather constant. Additionally, the interannual variation in the production of smaller fruit bodies was positively correlated with the overall fruit body production. The same two‐step pattern was recognized for R. japonica Hongo over 2 years. The possible contribution of this fruiting pattern to the establishment of genetic diversity in the genus was discussed.