Hanguana malayana is locally known as bakong ayer in Malay. There are six species in the genus in Peninsular Malaysia of which five are newly discovered (Nurfazilah et al., 2010). Hanguana malayana is a helophyte. Helophytes are plants that grow in marshes, partly submerged in water, so that they grow from buds below the water surface.
Bakong ayer is a widespread species ranging from Sri Lanka to the Philippines (Luzon) and to northern Australia and western Micronesia (Palau). It grows in open lowland areas in sunny but wet habitats, such as along muddy banks of large rivers or on the margin of freshwater bodies or in freshwater swamp forest from near sea level to 100 m altitude. At Tasik Merah, Perak, it is the dominant plant on the northern side of the lake where it forms very large clumps.
Hanguana malayana is a large perennial rhizomatous herb. It can be recognised by its giant leaves that are about 1-2 m tall which arise from runners in the waterlogged mud. The leaves are stiffly erect, sword-like, medium to dark green and flat to shallowly V-shaped with a sharply acute margin. The flowers are produced on an extensively branched terminal inflorescence with spike-like partial inflorescences, sometimes whorled. Like other monocotyledons, the flowers have six green or yellowish tepals. It is a dioecious plant, meaning that the stamens and ovaries are produced in unisexual flowers borne on separate plants. Nectar secretion occurs in both male and female flowers indicating insect pollination. The fruits of H. malayana are ellipsoid and when ripe are dark shining purple-red. They bear 1-3 fruits, each up to 5-10 mm long.