Elephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson synonym A. campanulatus (Roxb.) Blume) is a perennial herbaceous diploid Araceae (2n = 2× = 26, 28) that is found across Australasian and African countries [1, 2] (S1 Fig). The plant is distributed from close to the coastal line to an altitude up to 900 m above sea level and adapts to low light intensities [3,
4]. The crop exhibits wide agroecological adaptation to dry and moist lands [1, 5] and is abundant under trees shading home gardens, mixed gardens, secondary forests and agroforestry, as well as open fields [4, 6, 7].
Mature underground corm and young shoots are used locally as important cuisine, medicine and disinfectants in many Asian countries [4, 7±15]. The corm can be industrially exploited for various enzymes and phytochemicals [13]. The starch has a low glycemic index [16±17] that may benefit diabetic individuals. According to Matthews [18], elephant foot yams might have been used as food in Southeast Asia since the prehistoric era. The starchy corm is harvested at the dormant stage in the dry or winter season [4], with productivity reaching 50± 80 t ha-1 annually [7].

Along with vegetative growth in the rainy season, the plant releases some side-corms (cormels) [4]; thus, mature elephant foot yams are commonly surrounded by their smaller ramets. A single unisexual inflorescence emerges the fourth year after planting from the seed or cormel, and biannual flower bearing is common after the first flowering [4]. The reproductive system exhibits a dichogamous barrier to prevent selfing, and beetles assist with cross pollination in synchronous flowering [19±20], attracted by the rotten-meat odor released from the spadix [21]. Mature berries pertinently drop around mother plants; nevertheless, long-distance dispersal by birds has been reported [22].

Citation: Santosa E, Lian CL, Sugiyama N, Misra RS, Boonkorkaew P, Thanomchit K (2017) Population structure of elephant foot yams (Amorphophallus paeoniifolius (Dennst.) Nicolson) in Asia. PLoS ONE 12(6): e0180000. https://doi.org/10.1371/journal.pone.0180000