Egypt. J. Exp. Biol. (Bot.), 10(2): 125 – 132 (2016) © The Egyptian Society of Experimental Biology ISSN: 1687-7497 On Line ISSN: 2090 - 0503 http://my.ejmanger.com/ejeb/ DOI: 10.5455/egyjebb.20160628055424 RESEARCH ARTICLE Magda H. Gazer Lamiaa F. Shalabi THE ROLE OF POLLEN MORPHOLOGY IN THE IDENTIFICATION AND CLASSIFICATION OF PLANTAGO (PLANTAGINACEAE) ABSTRACT: Pollen grains of 14 species of Plantago (Plantaginaceae) collected from Saudi Arabia were examined using LM and SEM Microscopy. The size, shape, exine ornamentation and structure of aperture allowed the recognition of three distinct pollen types : Plantago albicans –type, Plantago coronopus – type and Plantago lanceolata – type. Key to these types and keys to species under each type were prepared. The results were used to test the taxonomic disposition of the species in existing classifications. KEY WORDS: Classification, Identification Keys, Plantago , Plantaginaceae, Pollen Morphology CORRESPONDENCE: Lamiaa F. Shalabi 1.Department of Biological and Geological Sciences, Faculty of Education, Ain Shams University, Cairo, Egypt. 2.Biology Department, Faculty of Sciences, Jazan University, Jazan, Saudi Arabia. E-mail: Flora_lamiaa@yahoo.com Magda H. Gazer Department of Botany, Faculty of Science, Suez Canal University, Ismailia, Egypt ARTICLE CODE: 13.02.16 INTRODUCTION: Plantago L. (Plantaginaceae) is a cosmopolitan genus with over 483 species, concentrated in temperate and high-elevation tropical regions (Tutel et al., 2005). Plantago species are distributed in all phytogeographical regions either as weeds in cultivation or in the more arid environments of deserts and oases where they represent a highly palatable and nutritious item to grazing animals (El-Gazzar et al., 2009). The plants are mostly annual or perennial herbs, or rarely subshrubs (Pilger, 1937; Meudt, 2012). Plantago is part of tribe Plantagineae (Albach et al., 2005) enlarged Plantaginaceae, the prevalent genus of the three genera on which family Plantaginaceae is based (Tutel et al., 2005; Boulos, 2005). The subgeneric classification of Plantago was carried out by Pilger (1937), Rahn (1978 & 1996), with the updates of Rønsted et al. (2002) and Hoggard et al. (2003). According to Pilger (1937) the genus is divided into two subgenera: Euplantago Harms and Psyllium Harms, while Rahn (1978) subdivided the genus into three subgenera including Plantago , Coronopus Rahn and Psyllium , who ranked the Mediterranean species of section Coronopus of Pilger (l.c.) as a third subgenus with two sections: Maritima and Coronopus . The most recent phylogenetic study of Plantago by Rahn (1996) relied upon 91 mainly morphological and embryological characters. Hair and seed characters were the most informative for his estimation of the infrageneric relationships. In all, 213 species, grouped in six subgenera and a number of sections and series, (Rønsted et al., 2002). Plantaginaceae are anemophilous, with forate pollen grains with 4 - 15 apertures (Rahn, 1996). Pollen studies clearly indicate that the genus Plantago is a homogenous taxon in accordance with the morphology of the genus (Faegri and Iversen, 1992). Pollen characters of Plantago were the subject of many previous studies (Basset and Crompton, 1968; Clark and Jones, 1980; Ubera et al., 1988; Perveen and Qaiser, 2004; Klimko et al., 2004; Hoghoughi et al., 2016). The genus Plantago is represented in flora of Saudi Arabia by 14