Pleione 6(2): 435 - 437. 2012. © East Himalayan Society for Spermatophyte Taxonomy ISSN: 0973-9467 Rediscovery of Blyxa japonica (Miquel) Maximowicz ex Ascherson et Gürke - a hydrophyte from Lakhimpur district of Assam, India K. Pagag1 and S. K. Borthakur 1 Botanical Survey of India, ERC, Shillong-793003 Department of Botany, Gauhati University, Guwahati-781014 Corresponding author; E-mail:kangs_2003@yahoo.co.in Revised 12.11.2012; Accepted 13.11.2012 Abstract Blyxa japonica (Miquel) Maximowicz ex Ascherson et Gürke of the family Hydrocharitaceae is reported here from Podumoni Beel in the Lakhimpur district of Assam after a gap of 114 years. The species has been described with photographs in the present communication. Key word: Blyxa japonica, rediscovery, hydrophyte, Assam INTRODUCTION Blyxa Noronha ex du Petit Thouars is represented by 9 species and it is distributed in tropical and subtropical regions of West and Central Africa, Malagasy to South and East Asia, Malaysia, North Australia and introduced in North America (Guha & Mondal 2005). Hooker (1885) described 7 species of Blyxa from British-India. In India the genus is represented by 3 species with one variety viz., Blyxa aubertii L.C. Richard, B. octandra (Roxburgh) Planchon, B. japonica (Miquel) Maximowicz ex Ascherson et Gürke and B. aubertii L.C. Richard var. echinosperma (C.B. Clarke) Cook et R. Lüönd (Guha & Mondal 2005). Naik (1964) reported 2 species from Assam viz., B. aubertii L.C. Richard and B. echinosperma (Cl.) Hook.f. Chowdhury (2005) enlisted B. aubertii Rich. and B. echinosperma (C.B. Clarke) Hooker f. from Assam. Another species viz., B. japonica (Miquel) Maximowicz is also reported from Assam and Meghalaya (Guha & Mondal 2005). During recent field works to explore the wetland flora of Lakhimpur district of Assam the authors collected a specimen from Padumoni Beel which was subsequently identified as Blyxa japonica (Miquel) Maximowicz ex Ascherson et Gürke of the family Hydrocharitaceae. There were two collections of the species from Tengali Bam Garden of Tinsukia district of Assam deposited in CAL (Tengali Bam Garden, 05.10.1898, Jakoba.Hook 53 and Jenkins, s.n.). In both of these herbarium sheets localities and other information are not clearly mentioned. From Meghalaya the species was collected from Nongpoh (37474, 30.07. 1964, J. Joseph, ASSAM). After scrutiny of literature and herbarium materials it is found that the species has been collected from Assam after a gap of 114 years since 1898. The voucher specimens have been deposited in the herbarium of Botany Department of Gauhati University (GUBH). Description along with other relevant information and photograph of the species has been provided here. 436 Rediscovery of Blyxa japonica from Lakhimpur, Assam 1 2 PLATE I. Blyxa japonica: Fig. 1. In the habitat with flowers; Fig. 2. A close-up view taking out of water K. Pagag & S. K. Borthakur 437 Blyxa japonica (Miquel) Maximowicz ex Ascherson et Gürke, in Engler et Prantl, Pflanzenfam., 2. 1: 253. 1889; Hartog in Steenis, Fl. Males., 1. 5: 393. 1957; Karthikeyan et al, Fl. Ind. Enum. Monocot. 80. 1989. Hydrilla japonica Miquel, Ann. Mus. Bot. 2: 271. 1866. [Plate I] Aquatic, herbs, monoecious. Roots fibrous. Stems up to 15 cm long, branched, tender. Leaves sessile with sheathing leaf base, light green, linear, serrated, acute, midrib distinct, veins parallel. Flowers solitary, emergent, bisexual. Sepals linear, 1.5 – 4 x 0.5 – 1 mm, green. Petals lanceolate , 4 – 6 x 0.5 – 1 mm. Stamens 3, filaments 0.4 mm; anthers 0.6 – 0.7 mm, linear. Ovary 1.3 cm; style 1.9 cm; stigma linear, 0.7 mm long. Flowers & Fruits: August – December Habitat: Marshy places. Distribution: India (E. India, Assam, Meghalaya),Nepal, Bangladesh, Thailand, Japan, China, Hong Kong, Taiwan, Malaysia, Indonesia,Vietnam, Korea, New Guinea, Italy, Celebes. Exsiccate: Podumoni Beel, North Lakhimpur, 07.10.2011 and 29.08.2012, KP 285 (GUBH), 286 (GUBH), 345 (GUBH). LITERATURE CITED Chowdhury, S. 2005. Assam’s Flora( Present status of a vascular plants); A partial documentation of the project Environmental Atlas of Assam, ASTEC, Guwahati Guha, R. & Mondal, M.S. 2005.Wetland Phytodiversity: A complete Guide to Indian Helobieae. J. Econ. Taxon. Bot., Addl. Ser. 24: 37 – 39. Hooker, J.D. 1885. Flora of British India. Volume 5. L. Reeve and Co. Ltd., Kent, London: Pp. 660 – 661. Naik, V.N. 1964. A note on Hydrocharitaceae of Assam and NEFA. Bull. Bot. Surv. India 6 (2-4): 301 – 303.