Previously part of a much larger species concept, Alangium villosum was separated into 13 geographically distinct species in the revision of Alangium section Rhytidandra by de Wilde and Duyfjes (2017). The current taxonomy is not reflected in some online data sources (GBIF 2023). This assessment follows the view presented by de Wilde and Duyfjes (2017) that A. villosum is restricted to Java; specimens from outside this area have been excluded from the assessment.

Alangium villosum is a presumably small tree, endemic to Java, western Indonesia. Across the majority of its range it occurs at elevations of c. 700–1,800 m asl, however, it likely occurs at lower elevations in some parts of its range, such as Barung Island. Based on known occurrences it has eight threatened locations, meeting the threshold value for Vulnerable under criterion B, an estimated extent of occurrence (EOO) of c. 55,294 km², exceeding the thresholds for threatened categories under criterion B1, and an area of occupancy (AOO) of 32 km², falling within the threshold values for Endangered under criterion B2. An area of habitat analysis provides an upper AOO estimate of 6,692 km². No numerical population data are available and the current population trend is unknown. It is not known to be severely fragmented or subject to extreme fluctuations. It has not been collected since 1939 and it is not known if the species has been actively searched for since then. There is an inferred continuing decline in the area, extent and quality of its habitat driven predominately by agriculture and illegal logging across its range. It is also threatened by increased incidence of forest fires in recent years. Despite its large EOO, and the area of habitat analysis indicating a large area of potential habitat within its range, a precautionary approach is applied and it is assessed as Vulnerable B2ab(iii).

Alangium villosum is endemic to Java, western Indonesia (POWO 2023). While it is likely to occur at lower elevations in some parts of its range, such as Barung Island, on mainland Java it is thought to occur at elevations of c. 700–1,800 m asl (de Wilde and Duyfjes 2017). This disparity is likely linked to widespread deforestation and habitat conversion across Java during the 19^th and 20^th centuries (Smiet 1990), which is suspected to have extirpated it from large parts of its range. The lack of recent collections make it difficult to assess its current distribution, however, based on extant occurrences it has an estimated extent of occurrence (EOO) of c. 55,294 km², an area of occupancy (AOO) of 32 km² and eight locations. Using an area of habitat analysis following Brooks et al. (2019) and a rescaled version of the Jung et al. (2020) global habitat map, its area of available habitat is estimated at c. 6,692 km². This is provided as an upper boundary for the AOO. Further research into this species' distribution is recommended

Java experienced widespread intensive deforestation during the 19^th and 20^th centuries. It is suspected that the species was extirpated from large parts of its range and experienced a population decline during this period. However, the lack of life history data makes it challenging to assess the impact of this decline with accuracy. Current numerical population data are unavailable and the current population trend is unknown. It is not known if the population is severely fragmented or subject to extreme fluctuations. Recent collections are unknown (de Wilde and Duyfjes 2017) and it is unknown if the species has been actively searched for in the recent period. Further research on the population size and dynamics of this species is recommended.

Alangium villosum is a tree, presumably of small stature based on other members of its section (de Wilde and Duyjfes 2017), though some sources state that it can grow to 10–20 m (Backer and Bakhuizen van den Brink 1965). It occurs in lower montane and montane rainforest flowering from August to December (de Wilde and Duyfjes 2017). Further research into this species' life history and ecology is recommended.

Java experienced extensive deforestation throughout the 19^th and 20^th centuries. It is estimated that only 3% of lowland forest and 57% of montane forest remain (Smiet 1990), with remaining habitat outside of protected areas generally being isolated in small forest fragments. Deforestation is ongoing across much of this species' range, with an estimated decrease of c. 3% since 2000, however annual rates decreased between 2019–2021 from c. 5.3 kha to 3.4 kha (Global Forest Watch 2023). It appears the designation of protected areas has been a key driver in reducing forest loss within some parts of its range, especially West Java (Higgingbottom et al. 2019). However, it should be noted that many of the protected areas within Java are situated at higher altitudes (Higgingbottom et al. 2019), and often outside this species' known elevation range. Additionally the effectiveness of protected areas varies across the range. A recent evaluation of the Bromo-Tengger-Semeru-Arjuno Biosphere reserve, which holds a substantial area of suitable habitat within East Java, identified small-scale agricultural expansion and illegal logging as threats to its integrity (Hakim and Soemarno 2017). Outside of protected areas, while rates of deforestation appear to be decreasing across its range, this is still viewed as a major threat to the species. The drivers of this habitat loss and degradation are varied but major contributors are small scale agriculture, illegal logging and small-scale commercial plantations (Austin et al. 2019). Additionally, forest fires, the incidence of which has increased across it range in recent years (Hakim and Soemarno 2017, Higgingbottom et al. 2019), pose an additional threat to this species' habitat. This is likely to be exacerbated in the future by projected climate change.

This species is not known to be utilized.

Alangium villosum is known to occur in at least two protected areas, with large areas of presumably suitable habitat held within the protected area network or designated under Indonesia's forest moratorium (UNEP-WCMC and IUCN 2023, Global Forest Watch 2023). While no specific conservation measures are known for this species, passive protection is assumed in these areas. While rates of loss are likely low, Hakim and Soemarno (2017) identified small-scale agricultural expansion and illegal logging as threats to the effectiveness of some protected areas. Further evaluation of protected area integrity across this species' range is recommended. It is reported to be held within several ex situ plant collections (BGCI 2023). However, it is not known if these records have been updated to reflect the taxonomy proposed by de Wilde and Duyfjes (2017), and research to confirm its presence within the ex situ conservation network is recommended.