 BANWA VOL. 10, NO. 1 (2013): 16–32 Te Flowering Habit of Nipa (Nypa fruticans Wurmb.) in Semi-wild Stands of the Davao Region, Philippines Junaldo A. Mantiquilla 1, *, Eufemio T. Rasco Jr. 1,2 , Abdel Majeed M. Mohammad Isa 1 , and Kristian Weller P. Licup 1 1 Department of Biological Sciences and Environmental Studies, College of Science and Mathematics, University of the Philippines Mindanao, Mintal, Tugbok District, Davao City 8022, Philippines. 2 Philippine Rice Research Institute (PhilRice), Science City of Muñoz 3119, Nueva Ecija, Philippines. * Corresponding author. Email: junaldo2003@gmail.com. Telephone: +63 82 293 0312 local 21. Received 25 July 2012; Revised 26 March 2013; Accepted 8 April 2013 Abstract Observations on the fowering characteristics of nipa (Nypa fruticans Wurmb.) were carried out on at least 70 randomly selected palms in various semi-wild stands found in the Davao Region, Philippines (i.e., Bago Aplaya, Ecoland, and Talomo) from April 2010 until February 2011. Te developmental stages of inforescence were identifed, described in detail, and arbitrarily divided according to morphological changes exhibited by the inforescence. Tese developmental stages are as follows: emergence (E) stage, stage 2 (S2), pre-anthesis (PA) stage, and the antheses stage, which is divided into the female receptivity (F) stage and the male anthesis (M) stage. Among the parameters measured for each stage include the length of the inforescence from base to tip, the number and length of staminate rachillae, and the number of female fowers. For morphological characteristics comparison of this monoecious inforescence, diferent stands in Carmen, Davao del Norte, were observed. Te Carmen stands were signifcantly more fecund compared to the Davao City stands. Te former had more female fower count (61 vs. 58 per pistillate head) and more staminate rachilla count (33 vs. 17 spikes) than the latter. Te fnal inforescence length in Carmen was signifcantly taller than in Davao City (117.5 cm vs. 84.3 cm), suggesting that the plants in the former had longer tapping potential for sap production. Te results have implications toward the future program of nipa hybridization to produce better varieties. Keywords: inforescence development; morphology; Nypa fruticans Wurmb.; Philippines; pollen characterization