Geospatial Distribution of Osmoxylon Miq. (Araliaceae) in the Philippines with Taxonomic Trait Updates of Species from Northern Mindanao

The Philippines hosts the greatest diversity of Osmoxylon species globally, yet the genus remains taxonomically understudied and lacks a modern comprehensive assessment. This study provides an integrated baseline on the geospatial distribution of Osmoxylon across the Philippine archipelago and presents updated taxonomic insights for species documented in Northeastern Mindanao. Occurrence records from published literature and reputable online repositories (GBIF, CDFP), combined with targeted field surveys in the Caraga Region, were used to map species distributions and evaluate key morphological traits. Eighteen species were recorded nationwide, exhibiting broad but uneven distribution patterns, with three taxa restricted to highly localized areas. Most species occurred in Type II climatic zones characterized by high year-round rainfall, indicating strong ecological affinity for moisture-rich environments. Ten species were documented through field surveys, including seven endemics and three native taxa, reaffirming Northeastern Mindanao as a significant biodiversity hotspot. Preliminary conservation assessments identified two species as Endangered, one as Near Threatened, and two as Least Concern, while the remainder lack formal evaluation. Mining and other anthropogenic pressures were identified as major threats, particularly for species confined to ultramafic and limestone habitats. The study highlights the need for intensified botanical exploration and recommends a nationwide, integrative taxonomic revision to refine species boundaries and support long-term conservation planning.