Angiosperms in Gobindaganj upazila of Gaibandha district, Bangladesh

Angiosperms at Gobindaganj Upazila of Gaibandha district, Bangladesh was studied from January to December 2018. An extensive floristic survey and angiosperms collection have been made throughout the study area. A total of 295 species belonging to 246 genera under 89 families were recorded. Plant habit analysis shows that herbs, shrubs, climbers and trees are represented by 47.45%, 15.93%, 12.20% and 24.40%, respectively. Distribution of angiosperm species in the families shows variation. Asteraceae is the most dominant family represented by 25 species, followed by Fabaceae (19 species), Euphorbiaceae (18 species), Cucurbitaceae (17 species), Acanthaceae (11 species), Solanaceae (11 species), Amaranthaceae (10 species) and Apocynaceae (10 species). 44 families are represented by a single species each while 37 families are represented by 2 to 8 species each. Status of occurrence has been recorded for proper conservation management and sustainable utilization of the taxa which show 218 (73.89%) to be common, 63 (21.35%) as rare, 10 (3.38%) as vulnerable, and 4 (1.35%) are found as endangered in the study area. For each species scientific name, voucher number, Bangla name, English name, habit, status of occurrence and flowering time were recorded. Introduction The flowering plants, also known as angiosperms, Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 64 orders, 416 families, approximately 13,000 known genera and 300,000 known species (Christenhusz and Byng, 2016). Angiosperms are seedproducing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies (derived characteristics). These characteristics include flowers, endosperm within the seeds, and the production of fruits that contain the seeds. Etymologically, angiosperm means a plant that produces seeds within an enclosure; they are fruiting plants, although more commonly referred to as flowering plants. The ancestors of flowering plants diverged from gymnosperms around 245-202 million years ago, and the first flowering plants known to exist are from 160 million years ago. They diversified enormously during the Lower Cretaceous and became widespread around 120 million years ago, but replaced conifers as the dominant trees only around 60-100 million years ago (Lindley, 1830). The angiosperms provide valuable pharmaceuticals. With the exception of antibiotics, almost all medicines are either derived directly from compounds produced by angiosperms or, if synthesized, were originally discovered in angiosperms. This includes some vitamins (e.g., vitamin C, originally extracted from fruits); aspirin, originally from the bark of willows (Salix; Salicaceae); narcotics (e.g., opium and its derivatives from the opium poppy, Papaver 1 Corresponding author: E-mail: drrahmanahmm@ru.ac.bd 286 SARKER AND RAHMAN somniferum; Papaveraceae); and quinine from Cinchona (Rubiaceae) bark. Sonic angiosperm compounds that are highly toxic to humans have proved to be effective in the treatment of certain forms of cancer, such as acute leukemia (vincristine from the Madagascar periwincle, Catharanthus roseus, Apocynaceae), and of heart problems (digitalis from foxglove, Digitalis purpurea, Plantaginaceae). Muscle relaxants derived from curare (Strychnos toxifera, Loganiaceae) are used during open-heart surgery (Naik, 2003). Over the last few decades several attempts have been made on the floristic studies in Bangladesh, particularly in the forest and protected areas (Khan and Afza, 1968; Khan and Banu, 1972; Khan and Hassan, 1984; Rahman and Hassan, 1995; Uddin et al., 2013; Khan and Huq, 2001; Uddin and Hassan, 2010; Tutul et al., 2010; Arefin et al., 2011; Uddin and Hassan, 2012). Studies on angiosperm flora in different districts and Upazilas of Bangladesh are limited (Islam et al., 2009; Rahman et al., 2013; Moniruzzaman et al., 2012; Rahman and Alam, 2013). However, there has been no floristic study in Gobindaganj Upazila of Gaibandha district, Bangladesh. Materials and Methods Study area: Gobindaganj is an upazila of Gaibandha district under the division of Rangpur. It is one of the largest upazila in Bangladesh including 17 unions and 1 municipality. Gobindaganj is located at 25.1333°N3' and 89.391°E. It is bounded by Ghoraghat and Polashbari upazilas on the north, Sonatala and Shibgonj upazilas on the south, Saghatta and Polashbari uazilas on the east, Panchbibi and Kalia upazilas on the west. One fourth of the total area of the upazila is included in the Barind Tract. It has 79464 households and a total area of 481.66 Sq. Km. As of 2011 Bangladesh census, Gobindaganj has a population of 714591. Males constitute 50.89% of the population, and females 49.11%. This upazila's adult population is 205204. Soil texture was determined by hydrometer method and soil P was measured in a 1:2.5. Soil water suspension measured by glass clatrode pH meter. This is the best soil for the growth of various plants. The study area has tropical monsoon climate. It is characterized by hot humid summers and generally mild winters and rainfall. The summer season commerce early in the March with the cessation of the Northerly wind. The winter season (November-January) which is cool and with little rainfall; the summer season (June-October) is warm and with no rainfall. The maximum monthly temperature can reach up to 37.78°C during April and minimum monthly temperature 7.78°C during January (BPC, 2001). Methodology: The work is based on fresh materials collected during twenty seven visits to Gobindhaganj Upazila of Gaibandha, Bangladesh from January 2018 to December 2018 to cover the seasonal variations. The visits covered all types of habitats, particular river bank, slope, village grove, fruit gardens and roadsides of the study area. Each trip lasted for eight days. Plant parts with either flower or fruits were collected using traditional herbarium techniques to make voucher specimens for documentation. Field identification of the collected specimens was confirmed comparing with herbarium specimens Rajshahi University Herbarium. Standard literature such as Hooker (1877), Prain (1903), and Ahmed et al. (2008-2009) were consulted for identification. For nomenclature Pasha and Uddin (2013) and Huq (1986) were also consulted. The specimens are deposited in the Herbarium, Department of Botany, Rajshahi University, Bangladesh for future reference. Results and Discussion Angiosperm diversity at Gobindaganj upazila of Gaibandha district, Bangladesh was investigated during January to December 2018. A total of 295 species belonging to 246 genera ANGIOSPERMS IN GOBINDAGANJ UPAZILA 287 under 89 families were recorded (Table 1). Of these, Magnoliopsida (Dicotyledons) is represented by 261 species under 213 genera and 73 families while Liliopsida (Monocotyledons) is represented by 34 species under 33 genera and 16 families. Habit analysis shows that herbs, shrubs, climbers and trees are represented by 47.45%, 15.93%, 12.20%, 24.40% species, respectively (Fig.1). Fig. 1. Recorded Magnoliopsida plants habit diversity in the study area. Fig. 2. Recorded Magnoliopsida plants status of occurrence in the study area. Distribution of angiosperm species in the families shows variation. Asteraceae is the dominant family represented by 25 species, followed by Fabaceae (19 species), Euphorbiaceae (18 species), Cucurbitaceae (17 species), Acanthaceae (11 species), Solanaceae (11 species), Amaranthaceae (10 species) and Apocynaceae (10 species) (Table 1; Fig. 3). 44 families are represented by a single species each, while 37 families are represented by 2-8 species each. Status of occurrence has been recorded for proper conservation management and sustainable utilization of the taxa, which show 218 (73.89%) to be common, 63 (21.35%) as rare, 10 (3.38%) as vulnerable and 4 (1.35%) as endangered in the study area (Fig. 2). Fig. 3. Dominant plant families in the study area. Based on the study, a preliminary list of angiosperm diversity at Gobindaganj upazila of Gaibandha district, Bangladesh is recorded. A total of 295 species belonging to 246 Genera under 89 families were found (Table 1). The collected information is comparable with the result of other studies in Bangladesh. A total of 243 species belonging to 195 genera under 95 families were recorded in Khagrachhari district (Islam et.al, 2009). A total of 374 species belonging to 264 genera under 84 families were recorded in Lawachara National Park (Uddin and Hassan, 2010). A total of 153 species belonging to 120 genera under 52 families were recorded in Runctia sal Forest (Tutul et. al, 2010). A total of 245 species belonging to 183 genera and 72 families were documented in Hobiganj district (Anefin et al., 2011). A total of 425 species belonging to 321 288 SARKER AND RAHMAN Table 1. Angiosperm Taxa in Gobindagaj Upazila of Gaibandha District, Bangladesh Scientific name and Voucher number Bangla name Family Habit Status of occurrence Flowering time MAGNOLIOPSIDA Michelia champaca L., PS 19 Champa Magnoliaceae Tree R Mar-Apr Annona reticulata L., PS 29 Nona, Ata Annonaceae Tree C Oct-Jan A. squamosa L., PS 37 Sarifa Annonaceae Tree C Mar-Jul Polyalthia longifolia (Sonn.) Thw., PS 21 Debdaru Annonaceae Tree C Mar-Oct Cinnamomum tamala Nees & Eberm, PS 49 Tejpata Lauraceae Tree R Feb-Oct C. verum J. S. Presl, PS 131 Daruchini Lauraceae Tree R Jan-Mar Litsea glutinosa (Lour.) Rob., PS 200 Menda Lauraceae Tree V Apr-Jan Peperomia pellucida (L.) H.B. & K., PS 44 Luchi Pata Piperaceae Herb C Jul-Sep Nymphaea nouchali Burm f., PS 132 Nilsapla Nymphaeaceae Herb C Jun-Oct Stephania japonica (Thunb.) Miers., PS 201 Akanadi Menispermaceae Climber R Jan-Dec Tinospora cordifolia (Willd.) Hook.f. & Thoms., PS 45 Gulancha Menispermaceae Climber R Jan-Oct Argemone mexicana L., PS 133 Sheyalkata Papaveraceae Herb C Feb-Jun Trema orientalis (L.) Blume, PS 202 Jibon Ulmaceae Tree C Jan-Jun Artocarpus heterophyllus Lamk.,