suborder Sclerodermatineae (Boletales)

This species is uncommon throughout its distribution. However in the last decade, significant declines in parts of its range, particularly in Central America, have drastically reduced the number of occurrences being recorded each year in those locations. This species prefers humid forests and is limited to increasingly small areas in Central America as climate change shifts the species’ habitat higher in elevation.  This is a beautiful fungus with cultural significance to native peoples of Hidalgo, Mexico, and is beloved by fungus lovers throughout its distribution due to its strange sporocarp morphology.

Calostoma cinnabarinum is a widely distributed species. This species has been reported in the United States from New England to the southern tip of the Appalachian Mountains and west to Texas. In the US, it is most common at higher elevations in the Appalachian mountains where oaks can be found, though a few isolated occurences have been reported along the Gulf of Mexico from Texas to Florida. In Central America, C. cinnabarinum is known from Mexico, Costa Rica, Panama, Honduras, Guatemala, El Salvador, and Belize. In Central America virtually all recorded sightings of this species occurred at an over 1000 meters in elevation, in humid cloud forests. In South America, the species has been documented in Colombia and Brazil. In Colombia, the mountains south of Medellin, and in Brazil, the eastern stretches of the country. C. cinnabarinum has also been documented in Asia, specifically Taiwan and mainland China, although Asian occurrences seem to be very rare and data on these occurrences is lacking.

Calostoma cinnabarinum is uncommon throughout its range. Based on recent recorded occurrences of Calostoma cinnabarinum, global declines are focused in Central and South America where increasing temperatures seem to be limiting the species’ range to increasingly high elevations or eliminating populations entirely (which may be the case in Costa Rica). Although the population seems to be large in the US based on the number of sightings, there is too little data to make assumptions about population trends.

This species forms ectomycorrhizal relationships with oaks and may also form associations with mosses. This species is most often found in humid forests. C. cinnabarinum is more common in mountainous areas with high annual rainfall. C. cinnabarinum’s preference for higher elevations is more pronounced in warmer regions. This is why in Central America, it is found almost exclusively above 1000 meters, but can be found at lower elevations in the northeastern United States for example.

In tropical regions, C. cinnabarinum is threatened by increasing temperatures. As is documented in Mexico, occurrences of C. cinnabarinum are becoming increasingly rare at lower elevations where it was once found. Similarly, increased aridity associated with climate change also threatens C. cinnabarinum, which thrives in humid forests with substantial annual rainfall. Furthermore, as humans are pressed to convert forest into farmland, again exacerbated by climate change, C. cinnabarinum will suffer habitat loss. Future declines should be expected throughout the species’ range as warming temperatures restrict C. cinnabarinum to higher elevations in Central and South America and the Appalachian Mountains of the US.

While the chief threat to C. cinnabarinum is climate change, habitat loss and deforestation, especially in Central American cloud forests, also significantly threaten C. cinnabarinum. In order to conserve C. cinnabarinum and other species into the future, these forests must be protected through international and national level conservation efforts. This may include linked enterprises and livelihood alternatives for locals affected by conservation efforts and the formation of protected areas.

Research to determine the number of individuals per unit area of suitable habitat would contribute greatly to a more accurate status of this species. Also, a more complete understanding of the biology and life history of C. cinnabarinum might allow us to better detect individuals and identify suitable habitat.

While historically this species has been consumed by some native peoples in Hidalgo, Mexico, it is far too uncommon to be of major economic importance.