PEER-REVIEWED ARTICLE bioresources.com Maulana et al. (2021). “Anatomy of Gigantochloa,” BioResources 16(2), 3596-3606. 3596 Variation of Anatomical Characteristics within the Culm of the Three Gigantochloa Species from Indonesia Muhammad Iqbal Maulana, a,# Woo Seok Jeon, b,c,# Byantara Darsan Purusatama, b Deded Sarip Nawawi, a Siti Nikmatin, d,e Rita Kartika Sari, a Wahyu Hidayat, f Fauzi Febrianto, a, * Jong Ho Kim, b Seung Hwan Lee, b and Nam Hun Kim b, * The anatomical features of three valuable commercial Gigantochloa bamboo species growing in Indonesia, including G. pseudoarundinacea, G. apus, and G. atroviolacea, were investigated by optical microscopy. The relative crystallinity and crystalline width of the culm of the bamboo species were examined by an X-ray diffraction method. These species contained vascular bundle of type III. Vascular bundle density was higher in the outer part of bamboo culm than in the inner. Fiber portion decreased from the outer part to the inner part and vice versa for the parenchyma and vessel portions. Fiber length of all species was higher in the outer part than the inner part of the culm. There was a significant difference in the fiber percentage between the bamboo species. Significant differences were also found in vessel diameter and parenchyma cell dimensions among the bamboo species. There was a slight difference in the crystalline properties between the outer and inner parts of the culm and among the bamboo species. All parameters showed a variation in the radial direction of the three bamboo culm but did not show a consistent tendency along the vertical direction. Keywords: Bamboo anatomy; Cell proportion; Gigantochloa; Relative crystallinity; Vascular bundle Contact information: a: Department of Forest Products, Faculty of Forestry and Environment, IPB University (Bogor Agricultural University), Bogor 16680, Indonesia; b: Department of Forest Biomaterials Engineering, College of Forest and Environmental Science, Kangwon National University, Chuncheon 24341, Republic of Korea; c: Division of Timber Engineering, National Institute of Forest Science, Seoul 02455, Republic of Korea; d: Department of Physics, Faculty of Mathematics and Natural Sciences, IPB University (Bogor Agricultural University), Bogor 16680, Indonesia; e: Surfactant and Bioenergy Research Center, IPB University (Bogor Agricultural University), Bogor 16143, Indonesia; f: Department of Forestry, Faculty of Agriculture, University of Lampung, Bandar Lampung 35145, Indonesia; # The first two authors contributed equally to this work; * Corresponding authors: febrianto76@yahoo.com; kimnh@kangwon.ac.kr INTRODUCTION Bamboos encompass a broad group of 1,250 species within 75 genera, most of which are relatively fast-growing in various types of soil, attaining stand maturity within five years. The stands of tall species may reach 15 m to 20 m, and the largest species, Dendrocalamus giganteus, grows to 40 m in height and 30 cm in culm diameter (Scurlock et al. 2000). The main distribution of bamboo comprises Africa and America, with 80% of the bamboo found in Asia Pacific including Indonesia (Mera and Xu 2014). Bamboo plays important roles in the lives of various peoples of the world. It is estimated that more than 2.5 billion people depend on bamboo for their economy and one billion people live in traditional bamboo houses (Lobovikov et al. 2007). Several studies show the potential of bamboo as an alternative to wood composite materials (Febrianto et al. 2012, 2015;