Pleione 5(1): 163 - 180. 2011. ISSN: 0973-9467 © East Himalayan Society for Spermatophyte Taxonomy Diversity of vascular plants in the Danga forest of Balurghat in Dakshindinajpur District of West Bengal, India Parasuram Kamilya Department of Botany, Balurghat College, Dakshindinajpur- 733101, West Bengal. E-mail- [email protected] [Received revised 05.02.2011; Accepted 20.03.2011] Abstract Floristic diversity of Danga forest of Danga Panchayat under Balurghat subdivision of Dakshindinajpur district of West Bengal has been made for the first time. Out of 216 species, 207 belongs to Angiosperms, dicot taxa 167 under 125 genera of 45 families and monocot taxa 44 under 31 genera of 14 families. Among Pteridophytes, luxuriant growth of Helminthostachys zeylanica covering about an area of 10 acres has been recorded. Among angiosperms few cultivated tree and majority of wild herbs, shrubs and climbers have been observed. Two cultivated taxa like Murraya koenigii and Tabernaemontana divaricata are growing throughout the forest floor probably getting a place congenial to them. Key words: Danga forest, angiosperms, Helminthostachys, identification. INTRODUCTION The district Dakshin dinajpur is placed at 25013.03/ N latitude and 88047.03/ E longitude. Total area, inhabited villages, Mouza, Municipality, Block, Panchyat Samity, Gram Panchyat and Gram sansad of this district are 2219 sq km, 1519, 1638, 2, 8, 8, 65 and 929 respectively (Mondol 2009). North, East & South sides of this district are surrounded by Bangladesh. Seven major rivers Atreyi, Jamuna, Tangon, Punarvaba, Braahmani, Shree and Bangshihari are flowing within this district. Some of them are actually the branches of Tista at Coochbehar from where they enter into Bangladesh at the Eastern part of this district and after flowing over this district they again enter into Bangladesh at South. Therefore, the soil of this district is of silty-sandy-loam helping luxuriant growth of different kinds of crops and vegetation. Danga forest is situated along the Eastern bank of the river Atreyi in Danga Panchyat under Balurghat Block (Map No. 1). The soil is mixed type having silty-clayey loam to laterite. The forest area is about 207.68 hectare and seminatural type having Range office at the Western Side. It is under the control of Rajganj Forest Division. There is no floristic record about this forest in the Range office. Even there is no published flora in this district after division of Dinajpur into Dakshin-dinajpur and Uttar-dinajpur, except the author in 2008 recorded the weed flora in the Atreyi river belt. Hence, an effort has been made to study the floristic diversity in this forest. MATERIALS AND METHODS The forest is situated about 5 km from Balurghat College. A thorough survey of vascular plants has been done from 2008 to 2010. Time to time the forest has been visited and specimens are collected and recorded with proper field numbers. Then they are pressed, dried and made into herbarium sheets. The taxa have been identified following different relevant floras and manuals (Prain 1903; Chakravarty 1957; Cook 1996; Kamilya & Paria 1994; Khan & Halim 1987; Hajra et al 1995, 1997; Sing et al 2000; Das 2004; Kamilya 2008; Bonger et al 2004; Bore & Raijada 1982; Ghosh 1997, 1998, 2001, 2005, and Ghosh et al 2008) and matched at CAL. Then search for relevant literature including recent ones for determining the correct names of taxa was followed as per mandatory articles of ICBN (Greuter et al 2000) with the aid of Appendix II and Internet. 164 Vascular plants diversity in Danga forest of Balurghat In the enumeration of flora the arrangement of families is followed principally according to Takhtajan (1997). Pteridophytes are only recorded. The artificial keys for genera and species of angiosperms are given and these are valid for the taxa studied only. Under each species only correct name is given by bold italics with reference to author’s name and field number along with the surname of the collector, abbreviated as ‘K’ for Kamilya within the parenthesis. Colour photographs of few specimens are given as fig 1, 2, etc. after field number. DAKSHIN DINAJPUR DISTRICT STATE OF WEST BENGAL BALURGHAT BLOCK (SUB DIVISION) Danga forest (Mouza map) Map 1: Study area ENUMERATION OF FLORA MAGNOLIOPSIDA ANNONACEAE Parasuram Kamilya 165 1. Large tree, densely hairy; ripened fruit bluishviolet……….......Miliusa velutina. 1a. Small tree or shrub, sparsely hairy to glabrous; ripened fruit orange or red ……………………………………………………………..Polyalthia suberosa Miliusa velutina (Dunal) Hook.f.et Thoms. (K666); Polyalthia suberosa (Roxb.) Thw. (K663) Fig. 1. MOLLUGINACEAE Glinus lotoides L. (K344); G.oppositifolius (L.) A.DC. (K394). Glinus : Key to the species: 1. Flower pedicelled; leaves glabrous………………………G. oppositifolius 1a. Flower sessile; leaves with woolly-tomentose hairs…………..G. lotoides AMARANTHACEAE 1. Bracts and bracteoles spinescent………………………...…...Aerva aspera 1a. Bracts and bracteoles not spinescent……………………………….…….2 2.Leaves opposite; plants suberect to prostrate; perianth papery ...... ...................................................................................Alternanthera 2a.Leaves alternate; plants erect; perianth not papery …………..Amaranthus spinosus Aerva aspera Spreng (K406); Alternanthera paronychioides St. Hil. (K 396); A. philoxeroides (Mart.) Griseb. (K466); A. sessilis (L.)R.Br. ex DC.(K499); Amaranthus spinosus L. (K603). Alternanthera : key to the speices : 1. Tepals1-nerved; leaves narrow-oblong or shortly oblong ………………...2 1a. Tepals3-nerved; leaves oblanceolate……………………A. paronychioides 2.Stem hollow; heads long-peduncled; leaves narrow-oblong …… …… …………………………………………………..…..A. philoxeroides 2a.Stem solid; heads almost sessile; leaves short-oblong …...………..A. sessilis CHENOPODIACEAE Chenopodium ambrosoides L. (K430). POLYGONACEAE 1. Plants prostrate, diffusely branched; leaves linear-lanceolate with curved tip;flowers purplish ………………………………….Polygonum plebeium 1a. Plants erect, branched; leaves without curved tips; flowers white …… …… ………………………………………………………….....Persicaria Persicaria barbata (L.) Hara (K376); P. hydropiper (L.) Spach (K698); P. orientalis (L.) Spach (K624); Polygonum plebeium R.Brown (K630). Persicaria : Key to the spices : 1. Leaves ovate, long-petioled; nutlets biconvex …………...… P. orientalis 1a.Leaves linear-oblong, sessile to subsessile; nutlets distinctly trigonous ..…2 2. Pseudospikes lax; cilia of the ochrea small or rudimentary …… …… ……………………………………………………..P. hydropiper 2a. Pseudospikes dense; cilia of the ochrea large……………..…….P. barbata HYPERICACEAE Hypericum japonicum Thumb. Ex Murr. (K678). 166 Vascular plants diversity in Danga forest of Balurghat NYMPHAEACEAE Nymphaea nouchali Burm. F. (K604); N. pubescens Willd. (K639). Nymphaea : key to the speices: 1. Leaves sharply sinulately toothed; anthers without appendages; night- flowering……………………………………………………...N. pubescens 1a. Leaves entire to bluntly dentate; anthers with terminal appendages; day flowering……………………………………………………N. nouchali MENISPERMACEAE 1. Stamens connate; leaves peltate; flowers in axillary umbellate cymes ……………………………………...……Stephania japonica var. discolor. 1a. Stamens free; leaves not peltate; flowers in axillary or terminal racemes or panicles...................................................................................................2 2. Carpels in male 3, rudimentary; leaves ovate ……… Tiliacora acuminata 2a. Carpels in male 0; leaves broadly-ovate-cordate …… Tinospora Stephania japonica (Thunb.) Miers var. discolor (Miq.) Forman (K708); Tiliacora acuminata (Lamk.) Miers (K691) Fig. 2.; Tinospora cordifolia (Willd.) Hook.f.et Thoms. (K704); T. sinensis (Lour.) Merr.(K798). Tinospora : Key to the species: 1. Plants densely tomentose; leaves with distantly 3-6 toothed …………………………………………………………………T. sinensis 1a. Plants glabrous; leaves entire ……………………………..….T. cordifolia ELATINACEAE Bergia capensis L. (K677). BARRINGTONIACEAE Barringtonia acutangula (L.) Gaertn.(K976). FLACOURTIACEAE Flacourtia ramontchi L’ Hér (K688). PASSIFLORACEAE Passiflora foetida Linnaeus (K640). CUCURBITACEAE 1. Tendrils simple; oil glands present on under surface of the leaves …………………………………………………………....Coccinia grandis 1a.Tendrils branched; oil glands absent on leaf ………………………………2 2. Petals with fimbrils at the margin; flowers white …… …… …………………………………………………….Trichosanthes 2a.Petals without fimbrils; flowers yellow………………Bryonopsis laciniosa Bryonopsis laciniosa (L.) Naud. (K685); Coccinia grandis (L.) Voight (K707); Trichosanthes cucumerina L. (K695); T. tricuspidata Lour. (K709). Trichosanthes : Key to the species: 1.Leaves pubescent; bracts small……………………………….T. cucumerina Parasuram Kamilya 167 1a.Leaves glabrous; bracts large…………………..……………T. tricuspidata CAPPARACEAE 1. Plants herbs, erect or prostrate without spines; flowers yellow or violet, …………………………………………………………………...….Cleome 1a.Plants bushy spiny shrub or lianas; flowers whitish-orange ………………………………………………………………...………Capparis Capparis zeylanica L. (K647) Fig. 3: C. viminea Hook.f.et.Thoms.(K698); Cleome rutidosperma DC. (K634); C. viscosa L. (K636). Capparis: Key to the species: 1. Scandant lianas with brownish hair on terminal part of the branches; flowers rosy- white; fruits large (±3-5 cm in diameter) ………………………………………………………………….C.zeylanica 1a. Bushy glabrous shrub; flowers white, small: fruit small (±1 cm in diameter) ……………………………………………………………C. viminea Cleome: Key to the species: 1. Prostrate glabrous herbs; flowers violet…………………C. rutidosperma 1a. Erect