Its hollow stipe suggests that it is a Craterellus not a Cantharellus (I. Olariaga Ibarguren in litt. 2022).

Cantharellus fuligineus was described from Sabah, Borneo. While there are some reports of it from elsewhere, these would not match with the distribution of its putative host plant (Lithocarpus havilandii) and are excluded pending further investigation. There is a lack of clear data with which to calculate the population size and trend, but the available information suggests that the population could be declining at a rate somewhere between the values that could justify a listing for Least Concern to Vulnerable under criterion A. The figures for primary forest loss in Sabah alone would tentatively suggest a rate of population loss in the range of 20-29% over a three generation period (50 years) and so C. fuligineus is assessed as Near Threatened under criteria A2c+4c. However, research is encouraged to investigate this further.

This species was first described from Sabah, Borneo (Corner 1966). Zhao et al. (2021) report it as a widely consumed species of China (in Yunnan, Qinghai, Sichuan and Tibet [or Xizang]), however this would not match up with the known distribution of its potential host (Lithocarpus havilandii), which is only known from Borneo and Sulawesi (POWO 2023), so further verification is required.

Without clearer information, a detailed estimate of the population size is not possible at this time. Based on the rapid loss of forest in Sabah, a population decline can be suspected, however. Estimating the rate of decline of forest cover within the range of Cantharellus fuligineus, is difficult without a full, clear indication of its true range, but a tentative value can be calculated based on the currently available data.

World Resources Institute (2023) shows rapid loss of forest cover at 30% canopy cover in Sabah. The total amount of primary forest cover within Sabah between 2001 and 2022 declined by 11% (World Resources Institute 2023), and while this does include all forest types, not just high-altitude, given the historical loss of lowland primary forest cover (see Gaveau et al. 2014), it is likely that most primary forest that remains to be lost would be at higher altitudes. This would equate to an overall loss of 26.2% over a three generation time period (50 years; per Dahlberg and Mueller 2011). For a comparable figure, primary forest cover declined by 18% between 2001 and 2022 in Sarawak (World Resources Institute 2023). Primary forest loss figures for Kalimantan specifically are not available via this source (although the higher altitude areas in central Borneo do appear to be less impacted). For the sake of this assessment, pending more accurate data, a precautionary attitude is taken and the figures for primary forest loss in Sabah are used as a tentative proxy, noting that they will not represent a 1:1 calculation for the rate of decline in C. fuligineus. Thus a past and ongoing rate of decline of 20-29% over three generations is very tentatively suspected.

This species has been noted as being characteristic of higher altitude forest with Lithocarpus havilandii (Corner 1966, I. Olariaga Ibarguren in litt. 2022).

In general the forests of Borneo have suffered high rates of deforestation (see World Resources Institute 2023), with significant threats coming from conversion to non-timber plantations, logging and fire (Gaveau et al. 2014). The exact contribution of each of these to the rate of decline of Cantharellus fuligineus is unknown, but it is suspected that all would be impacting the species to some degree if it is found across Sabah, or even more widely across Borneo.

It has been reported as an edible or medicinal species in China (Zhao et al. 2021), but further confirmation that these records truly correspond to Cantharellus fuligineus is required. Essentially, therefore, until this is confirmed it is not known if C. fuligineus sensu stricto is used.

Ensuring effective protection of remaining areas of high-altitude forest in Sabah will be important for this species. Further research is required to ascertain the full distribution of the species, and to investigate whether it is present in China. If the latter is confirmed by genetic studies then further work into its potential associated plant species would be needed. Taxonomic work to confirm generic status would also be useful.