Bayok is a medium tree reaching a height of four to 10 meters.
Its leaves are oblong to oblong-obovate, grow 15 to 25 centimeters in length, abruptly pointed at the apex, and broad or heart-shaped at the base. The upper surface of the blade is smooth, and the lower surface is pale and densely hairy.
The flowers are white, measure 12 to 14 centimeters long, and borne singly or in pairs in the axils of the leaves.
The fruit is about 15 centimeters long, woody, and five-angled.
The species is common and widely distributed in the Philippines. It is mostly found in Cagayan to Camarines Provinces in Luzon, Mindoro, Palawan, Ticao, Masbate, Guimaras, Negros, Mindanao, and Basilan. It is commonly found in forests at low and medium altitudes.
Bayok wood is used for jointing, flooring, cladding, making of furniture and tool handles, and manufacture of plywood. It is also used in ship- and bridge-building and construction of beams, joints, and rafters. It is also suitable for matches and the production of wood-wool board. The pulp is suitable for making paper. The bark of this tree is used for dyeing fish nets and cloth.
Bark and flowers, charred and mixed with the glands of banuyo (Mallotus philippinensis) are employed in smallpox to discharge the pus. The tannin-rich leaves and bark are used in traditional medicine as poultice against itch and wound infection and taken internally to treat dysentery.