Hydnophytum orbiculatus or H. orbiculatum.

[Derrick]

H. orbiculatus Elmer, (Adolf Daniel Edward Elmer) as originally published in Leafl. Philipp. Bot. vol. 5, Rubiaceae from Mt Urdaneta, p1860, (1913) (Leafl. Philipp. Bot.)

http://www.biodiversitylibrary.org/item/6764#page/308/mode/1up.

Isotype. http://www.usna.usda.gov/graphics/usna/Research/Herbarium/Specimens/0026662.jpg

OR.

H. orbiculatum Elmer. This is the correct neuter gender spelling.

Collection. At 609.6 m. (1990 ft.) on Giwantanan Knoll, in Manobo. (Mt. Urdaneta), Agusan Prov., Mindanao Island, Philippines. Isotype. http://plants.jstor.org/stable/10.5555/al.ap.specimen.ny00131930

Giwantanan Knoll is described here in “Leaflets of Philippine Botany vol.7. (1914-1915.) http://www.archive.org/stream/mobot31753002430558/mobot31753002430558_djvu.txt

Collection. Presumably on Mt Urdaneta, inland from Cabadbaran City, Agusan Province, Mindanao Island. Philippines. Type. http://plants.jstor.org/stable/10.5555/al.ap.specimen.bm000945559

Here referred to H. formicarum Jack, a collection on Mount Bulusan, Irosin Municipality, Sorsogon Province, Luzon Island, Philippines. http://plants.jstor.org/stable/10.5555/al.ap.specimen.gh00096759

Mt Bulusan http://plants.jstor.org/stable/10.5555/al.ap.specimen.bm000945560

Malabo, Valencia, Negros Orientale Prov. http://plants.jstor.org/stable/10.5555/al.ap.specimen.f0069567f

Type. http://kiki.huh.harvard.edu/databases/specimen_search.php?mode=details&id=72232