Cotylelobium melanoxylon is a tropical rainforest tree found in Maritime Southeast Asia. The name melanoxylon is derived from Greek (melanos = black and xylon = wood) and describes the dark heartwood. It is a very good quality timber, as it has very hard and heavy as well as durable wood. C. melanoxylon is a tall emergent tree, up to 60 m, found in mixed dipterocarp forest on yellow sandy soils. It also occurs as a smaller canopy tree in kerangas forest on podsols. The tree occurs in at least three protected areas (Lambir National Park, Gunung Mulu National Park and Kabilli-Sepilok Forest Reserve). Local names of the tree include Resak tembaga in Malay and Khiam (เคี่ยม) in Thai. The tree is the provincial symbol tree of Surat Thani Province, Thailand.