Kingdom: Fungi
Subkingdom: Dikarya
Division: Basidiomycota
Class: Agaricomycetes
Subclass: Phallomycetidae
Order: Phalalles
Family: Phallacae
Genus: Clathrus

This species was first characterized in 1801. Alternate names include: Clathrus flavescens (named by Christiaan Hendrick Persoon in 1801), Clathrus cancellatus (published by Elias Fries in 1823), Clathrus nicaeensis (published by Jean-Baptiste Barla in 1879), and Clathrus ruber var. flavescens (published by Livio Quadraccia and Dario Lunghini in 1990).

Basionym: Clathrus ruber P. Micheli ex Pers

Clathrus ruber, a distinctive-looking fungus, has a range and integrity of habitats that fluctuates considerably. More research is needed to determine specific C. ruber population trends on a regional and global scale and to evaluate the impact of environmental factors on such trends.

The biomes this species is found in are temperate broadleaf and mixed forest, Mediterranean forest, woodlands and scrub, tropical and subtropical moist broadleaf forests, temperate conifer forests, and coastal forests.

This species is mainly found in regions such as southern and central continental Europe, including France, Spain, Portugal, and Italy. In recent years, this species has been introduced to other regions in Europe, including Austria (Essl 2018) and Poland (Solarz 2019). This species is also found in parts of the Mediterranean (spreading to Iran through Turkey) and coastal areas of continental North America.

This species used to be considered rare due to the low frequency of sightings, but now may be less common in certain areas of the world due to species introduction, spread, and relative colonization of new habitats. For instance, this species has recently become more present in Ukraine (see Regional Status).

This species occurs in a variety of habitats which change with different frequencies. Some habitats are fairly common, such as grasses, and are increasing, such as disturbed sites that are eventually reclaimed. Other habitats this species occurs in are decreasing, such as established forests.

The average and range of number of global genetically unique mycelia/locations is approximately 100 - 150. The length of the time period over which the change is compared is 20 years.

This fungus has a saprotrophic life mode. The substratum consists of decaying wood, dead pine leaves, dead pine needles such as P. pinea (Güngör 2011, Lantieri 2009, Ortega 2005), and other decaying organic debris. The species is found in varying habitats, including woodchip-laden soil, among grasses (Lantieri 2009), near lawns, at the border of untilled land (Lantieri 2009), reclaimed land including anthropogenically transformed territories such as old parks (Heluta 2019), wet and shadowy meadows, and in consolidated inner dunes with P. pinea reforestations (Güngör 2011, Lantieri 2009, Ortega 2005). This species originally diffused only under warm climate but later collected under different climatic conditions. It is found in thermo-Mediterranean dry to sub humid levels, and the highest densities are observed in coastal areas.

The main threats to this species are indirect and stem from habitat alteration. Deforestation impacts the amount of dead leaf substrate for this species to use. Increased industrial activity impacts the amount of grasses and nutrient-rich soil that the fungus can use. Improper reclamation of disturbed industrial sites diminishes the areas this fungus can grow in. For populations of this fungus in coastal areas, rising sea levels decrease the area this fungus can grow in. A potential smaller threat to this fungus is more direct. The noisome odor and strange appearance of the fungus itself may spur people who encounter them to destroy them or create conditions where fungus growth is unsuitable, as is the case with landscaping (Carroll 2020).

Conservation actions to preserve this species should be centered around habitat protection. This includes protecting old growth, forests and veteran trees in general, especially those where defined and reliable clusters of C. ruber are documented; reclaiming industrially disturbed ground such as mining or construction sites, and reforesting trees such as Pinus sp. where C. ruber is known to grow. Additional conservation efforts can be towards general education and spreading awareness of this species.

More research is needed on how C. ruber dispersion is impacted by its habitat. This includes determining relative amount and speed of specimen propagation in coastal regions versus in terrestrial habitats, how C. ruber specimen frequency changes in reclaimed industrial settings, how C. ruber specimen frequency changes in locales of previous sightings, and whether C. ruber is observed in new types of habitats not previously documented (a measure of how adaptable this species is).

C. ruber has been observed to be localized with primarily Pinus sp. trees. Additional research is needed to determine if C. ruber reliably grows in the presence of other types of trees.