Lactifluus pulchrellus is part of a species complex with L. igniculus, both of which have only been recorded rarely. Lactifluus pulchrellus is known from only 2 records, one each from Thailand and Vietnam, both growing in forests with Dipterocarpaceae. Due to the small number of records, and possible confusion with L. igniculus, the species is assessed as Data Deficient.
Lactifluus pulchrellus is characterised by its small basidiocarps (cap diam. 2-11.5 mm) and warm red to orange colors, which are very unique in Lactifluus sect. Gerardii. The species is similar to Lf. igniculus, but Lf. igniculus has whitish velutinous hairs covering its basidiocarp surface (Morozova et al. 2013). The spore ornamentation also allow to discriminate both species. Lf. pulchrellus has low and irregular rounded warts, whereas Lf. igniculus has almost acute echinulate spores (De Crop et al. 2018).
The species might have small population size or the species might be unknown in natural forest as they have striking small basidiocarp. Up to present, the species is only known from the locality of the type specimen.
The species is known from one specimen collected from Chiang Mai, Buatong waterfall and Chedsi spring national park. (northern Thailand), and one from central Vietnam. Although brightly colored, it is small and it is likely undercollected.
Although, dry dipterocarpus forest is one of common tropical dry forests in Thailand, Lf. pulchrellus has only been reported once from Thailand. The species was discovered and described based on single collection by De Crop et al. (2018) and is never been reported from any other locality. The lowland dry dipterocarp forest is one of important tropical dry forest in central and northeastern Thailand. However, the size of this forest type has been declining, particularly in low elevation areas in central Thailand. A single collection was recorded from mixed forest with scattered dipterocarp in central Vietnam. Because of its small size it likely has been over-looked and occurs in additional sites. The potential trend of this species could be decreasing due to disturbance of lowland dipterocarp forest caused by land use changes in many areas in region.
Population Trend: Decreasing
In Thailand the species is found on naked stony soil under Dipterocarpus tuberculatus forest at an elevation of 500 m. The mixed forest that the species is recorded from in central Vietnam in a river valley with species of Dipterocarpacea at elevation of 360 m.
The main threat to Lf. pulchrellus is declining habitat and fragmentation due to the decrease of populations of host trees caused by forest degradation, unintentional wildfires and changing rain fall patterns.
The size of lowland dry dipterocarp forest have been declining in several areas of Thailand due to land use changes caused by human activities. In recent years, Thailand has been experiencing severe wildfires in many forests in northern Thailand during dry season. This occurrence has negative effect on population size of host tree and soil quality. Therefore, habitat protection and efficient forest management planning are necessarily implemented in order to reduce habitat loss and regenerate the fungal host tree in disturbed areas. In addition, awareness to locals on the persistence of the species and suitable habitat are necessary. The species is only known from a protected area in Vietnam, but habitat protection is needed as the species likely occurs at other sites.
The study on biogeography and ecology of the species are required in order to more understand the actual distribution and population size of the species.
Morozova O.V., Popov E.S., Kovalenko A.E. (2013). Studies on mycobiota of Vietnam II. Two new species of Lactifluss (Russulaceae) with pleurotoid basidiomata. Mikologiya I Fitopatologiya 47:92-102.