Jurnal Biodjati 8(2):262–272, November 2023 http://journal.uinsgd.ac.id/index.php/biodjati e-ISSN : 2541-4208 p-ISSN : 2548-1606 Spores Morphological Characteristics of Several Ophioglossaceae and Psilotaceae Fern in "Eka Karya" Botanical Garden - Bali Ni Kadek Rika Pramesti1, Wenni Setyo Lestari2, Eniek Kriswiyanti3, I Made Saka Wijaya*4 INTRODUCTION Ferns are primitive plants that already have a vascular system, have a wide distri- bution on earth, and have various life forms such as terrestrial, epiphytes, and aquatic forms (Nitta & Ebihara, 2019; Sofiyanti et al., 2019a). These plants can reproduce through spores formed inside sporangia (Sharma, 2012). The germination of spore involving Citation Pramesti, N. K. R., Lestari, W. S., Krismiyanti, E. & Wijaya, I. M. S. (2023). Spores Morpholog- ical Characteristics of Several Ophioglossaceaeand Psilotaceae Fern in "Eka Karya" Botanical Garden - Bali. Jurnal Biodjati, 8(2), 262–272. DOI: 10.15575/biodjati.v8i2.29453 *Corresponding author Abstract. Ferns of Ophioglossaceae and Psilotaceae families can be found in the "Eka Karya" Botanical Garden, Bali as a collection or naturally growing in the botanical garden and those families are taxo- nomically classified as primitive ferns. The morphological character- istics of the family of Ophioglossaceae and Psilotaceae or even other types of ferns can be known through the morphological characteris- tics of the spores. This study aimed to characterize the spore morphol- ogy of the Ophioglossaceae and Psilotaceae fern of The "Eka Karya" Botanical Garden. Observation of the morphological characteristics of spores in the "Eka Karya" Botanical Garden was carried out by a simple method without acetolysis. The result of six types of fern plants from the family of Ophioglossaceae and Psilotaceae showed similari- ties to the spore unit, monads. Each family has unique characteristics that can be used to differentiate each other. The family Ophioglos- saceae has a variety of spore colors, trilete spore types, mostly glo- bose-shaped (except for one species the trilobate), the average polar diameter is 28.59±2.19 – 31.00±2.49 μm and the equatorial diameter is 32.85±1.74 – 37.55± 1.71 μm, the P/E ratio is 0.79-0.87, the shape based on the P/E ratio is suboblate, the spore size category is medi- um and has radial symmetry. For the family Psilotaceae, has a pale yellow-green spore color, monolete type, elongate-ellipsoidal shape, average polar diameter of 26.20±2.76 –29.81±2.96 μm and equato- rial diameter of 52.98±2.55 – 63.31±4.65 μm, P/E ratio of 0.47-0.49, shape based on P/E ratio i.e. peroblate, large spore size category and has bilateral symmetry. Those characteristics are valuable taxonomic data that can be used as diagnostic characters for the identification of the families Ophioglossaceae and Psilotaceae. Keywords: fern spore, monolete spore, palynology, primitive fern, trilete spore 1,3,4 Biology Program, Faculty of Mathematics and Natural Sciences, Universitas Udayana. Jl Raya Kampus Unud Jimbaran, Kuta Selatan, Badung-Bali, Indonesia, 80361, 2 Research Center for Biosystematics and Evolution - National Research and Innovation Agency, Jl. Raya Jakarta- Bogor Km. 46, Cibinong, Bogor, West Java, Indonesia, 16911 e-mail: 1 rika.pramesti01@gmail.com 2 wenn002@brin.go.id 3 eniek@unud.ac.id 4 *sakawijaya@unud.ac.id Received: September 06, 2023 Revise from: September 08, 2023 Accepted: November 02, 2023 Copyright © 2023 Jurnal Biodjati This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)