Morphological Differentiation between Nibung (Oncosperma tigillarium (Jack) Ridl), A Mascot Flora of Riau Province, and Its Closed Related Species, Bayas (Oncosperma horridum (Griff) Scheffer)

Abstract

Nibung and Bayas plants are members of the Arecaceae family, which is characterized by monocots, solitary or clumped stems, pinnate compound leaves, and flower frames. The province of Riau contains Nibung (O. tigillarium). Nibung (Oncosperma tigillarium) and Bayas (Oncosperma horridum) are members of the same family, but their morphology and habitat are distinct. This study seeks to determine the morphological distinctions between Nibung and Bayas plants found in the province of Riau, as well as their distribution. This investigation utilized field samples collected from two locations: Rantau Bertuah Village and Tanjung Medang Village. Additional analysis of morphological characters, notably diagnostic characters, and distribution data obtained from the GBIF website using secondary data. The results revealed morphological distinctions between O. tigillarium and O. horridum, particularly in terms of habitat, leaf arrangement, stem texture, and thorn texture. In contrast to the leaves of O. horridum, O. tigillarium leaves are arranged (facing) in the opposite direction. The stem of O. tigillarium is silky, whereas that of O. horridum is fibrous and textured. The thorns of O. tigillarium have a smooth and thin texture, whereas those of O. horridum are rough and dense. In addition, Nibung and Bayas plants have strikingly different distributions. O. tigillarium grows in marshy zones along the coast, whereas O. horridum grows on mountain slopes and plateaus.