FIRST RECORD OF HOYA MELIFLUA (BLANCO) MERR. (APOCYNACEAE, ASCLEPIADOIDEAE) IN THE NATURAL ECOSYSTEMS OF BATANGAS IN LUZON ISLAND, PHILIPPINES, WITH NOTES ON ASSOCIATED FLORA

The Philippine islands host a significantly high concentration of native and endemic Hoya species. However, there are no previous records of this genus in the natural ecosystems within the province of Batangas, Luzon Island. The present study pioneered the exploration of Hoya plants and their associated communities in Batangas. A route-walk method was employed within the forests of Lobo, Batangas, to document Hoya species. Morphological characteristics, habitat, host plants, substrates, and associated flora were also recorded. Only one species was identified, Hoya meliflua (Blanco) Merr., with material deposited in the Batangas State University – The National Engineering University Lobo Campus Herbarium (Reg. #: Pasado 001). The morphology and other plant references and databases confirmed its identity. The study found that the individuals of H. meliflua in Lobo inhabit the secondary riverine forests along ecotourism sites, with Schizostachyum textorium (Blanco) Merr., Ficus balete Merr., Tectona philippinensis Benth. & Hook.f. ex Merr. and Pterospermum diversifolium Blume as the major host plants. The assessment of the associated flora revealed 46 species, of which 100% were natives, 13% were Philippine endemics, and 14% were threatened nationally and internationally. The conservation of H. meliflua in Batangas can be improved by mainstreaming its importance as an ornamental plant and a key biodiversity species within ecotourism sites. Further studies can help in revealing the presence of other Hoya spp. on the island.