Katrina ji is right! This is Hydnophytum formicarum of Rubiaceae. Popularly known as 'Ant Plant'. (Myrmecodia tubers are spiky).
Recently I came across this plant in Vietnam where it is listed under the threatened category. It is distributed from Andaman islands to S. Thailand, Myanmar, Vietnam, Malaysia, Indonesia, Philippines and Australia. This plant is of interest to botanist and ecologists owing to the symbiotic association of ants and the plant. Regards, Ritesh.
