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 viscid herbs; flowers yellow………………………………C. viscosa

TILIACEAE 1.Leaves rhomboid without basal cilia; fruit elongated, without spines……………………………………………….…Triumfetta rhomboidea 1a. Leaves ovate with two basal cilia; fruits globose, prickly ……………………………………………………………Corchorus aestuans Corchorus aestuans L. (K646); Triumfetta rhomboidea Jacq. (K64).

DIPTEROCARPACEAE Shorea robusta Gaertn.f. (K671).

STERCULIACEAE Melochia corchorifolia L. (K678). BOMBACACEAE Bombax ceiba L. (K660).

MALVACEAE 1. Plants with epicalyx; flowers orange…………………………..Urena lobata 1a. Plants without epicalyx; flowers yellow …….…………………………Sida Sida acuta Burm.f.(K713); S. cordata (Burm.f.) Borss. (K700); S. rhomboidea Roxb. Ex Fleming (K701); Urena lobata L.(syn. U. sinuata L.) (K648). Sida : Key to species : 1. Stem trailing; leaf base cordate …………………………………S. cordata 1a. Stem erect or suberect; leaf base acute …………………………...……….2 2. Leaves nearly glabrous, narrow, acuminate; peduncle as long as petiole …………………………………………………………………...…S. acuta 2a. Leaves pubescent beneath, ovate-acute; peduncle longer than petiole…………………………………………………..……S. rhomboidea

MORACEAE 1. Anthers in bud reversed; flowers solitary (@&) or peduncled head (B&) ……………………………………………………………. Streblus asper 168 Vascular plants diversity in Danga forest of Balurghat 1a. Anthers in bud erect; flowers (@&& B&) inside the closed receptacle ……………………………………………………………….….Ficus hispida Ficus hispida L.f. (K702); Streblus asper Lour. (K747).

EUPHORBIACEAE 1. Trees, ………………………………………………………………….….2 1a. Shrubs or herbs …………………………………………………………...3 2. Leaves opposite with unequal petioles……………… Trewia nodiflora 2a. Leaves alternate …………………………………………………………..4 4. Leaves compound, 3-foliate ………………..…………..Bischofia javanica 4a. Leaves simple ………………………………………………………….…5 5. Glabrous; stamens 2-5; fruit drupe ……………………...Antidesma acidum 5a. Hairy; stamens 2-5; fruit capsule ………………….Gelonium multiflorum 3. Plants shrubs or undershrub or climbers …………………………………6 3a. Plants herbs ……………………………………………………Phyllanthus 6. Plants climbers with stinging hairs ……………...………Tragia involucrata 6a. Plants shrubs or undershrubs with hairs otherwise ………………………7 7. Hairs simple and glandular; flowers red; leaves palmately 3-5-lobed …… …… ………………………………………………………..….Jatropha gossypifolia 7a. Hairs pubescent; flowers white; leaves simple ……………………………8 8. Fruits orange-red when ripe ……..……………………Breynia rhamnoides 8a. Fruits black when ripe………………………………..Kirganelia reticulata

Antidesma acidum Retz. (K676); Bischofia javanica Blume (K658); Breynia rhamnoides Mull. Arg.(K684); Gelonium multiflorum A.Juss. (K624); Jatropha gossypifolia L.(K710); Kirganelia reticulata Bail. (K659); Phyllanthus fraternus Webster (K697); P. urinaria L. (K625); P. virgatus Foster. F. (K699); Tragia involucrata L. (K712); Trewia nodiflora L. (K672).

Phyllanthus : Key to species : 1.Prostrate herbs ; leaves linear-oblong to oblong-lanceolate ……...P. virgatus 1a.Erect herbs with oblong leaves …………………………………………….2 2.Stem angular with reddish-tinge at the basal part; leaves closeset at the basal part …… …… …………………………………………………….....P. urinaria 2a.Stem ± round, green throughout; leaves absent on the basal part …… …… ………………………………………………….……….P. fraternus

COMBRETACEAE Terminalia arjuna (Roxb. ex DC.) Wight & Arn. (K674).

LYTHRACEAE Lagerstoemia speciosa (L.) Pers. (K711).

ONAGRACEAE Ludwigia adscendens (L.) Hara (K623); L. perennis L. (K651). 1.Plants erect herbs in marshy areas; stem angular; leaves lanceolate …………………………………………………………………...…L. perennis 1a. Plants floating on marshy areas; stem round spongy; leaves oblong-elliptic ………………………………………………………….………...L.adscendens

MYRTACEAE 1.Trees with narrow- lanceolate leaves; fruit turbinate ….Eucalyptus globulus Parasuram Kamilya 169 1a.Trees with elliptic or ovate-elliptic leaves; fruit broadly elliptic …………………………………………………………..…….Syzygium cumini Eucalyptus globulus Labill. (K661); Syzygium cumini (L.) Skeels (K649).

FABACEAE CAESALPINIOIDEAE 1.Trees or herbs or under shrubs; without spines; leaves 1-pinnate …….Cassia 1a.Lianas with straight or hooked abundant spines; leaves 2-pinnate ……………………………………………….………Caesalpinia bonduc Cassia siamea Lam. (K694); C. sophera L. (K706); C. tora L. (K678); Caesalpinia bonduc (L.) Roxb. (K609).

Cassia : Key to species : 1.Trees; leaf bases without glands ……………………….………….C. siamea 1a. Herbs; leaf bases with glands …………………………………….……….2 1.Leaflets obovate 3-pairs ……………………………………………….C.tora 2a. Leaflets ovate-lanceolate, 6-12 pairs ………………………...…C. sophera MIMOSOIDEAE 1.Trees; spines absent; phyllode present ………...……..Acacia auriculiformis 1a. Shrubs or herbs, spiny, phyllode absent ……………………….….Mimosa Acacia auriculiformis A. Cunn.(K698); Mimosa intsia L. (K703); M. pudica L. (K692).

Mimosa : Key to species: 1.Woody herbs; pinnae digitately arranged ………………...……….M. pudica 1a. Large shrubs; pinnae pinnately arranged ………………………....M. intsia FABOIDEAE 1.Twining herbs with or without woody base ………………………...………2 1a. Trees or lianas or shrubs or herbs …………………………..……………3 2.Leaves subdigitately 3-foliolate; flowers yellow……..Cajnus scarabaeoides 2a. Leaves even-pinnate with more than 3-leaflets; flowers white ………………………………………………….……………Abrus precatorius 3.Trees or lianas ……………………………………………...……………….4 3a. Herbs or shrubs …………..………………………………………………..5 4.Lianas; inflorescence axis larger than leaf ……………….....Derris scandens 4a. Trees; inflorescence axis smaller than leaf ……………………………….6 6.Leaf axis zigzag with upper most leaflet large …………….Dalbergia sissoo 6a.Leaf axis straight, upper most leaflet not large …………Pongamia pinnata 5.Leaf simple; stipules white, scarious …………………Alysicarpus vaginalis 5a.Leaf compound; stipules otherwise …………………..……………………7 7.Plants prostrate or suberect ……….……..………………….………………9 7a.Plants erect …………………………….……………………………….…..8 8.Flowers purple; leaves compound ……………………...Tephrosia purpurea 8a.Flowers white; leaves simple …………………………..Flemingia chappar 9.Leaflets rhomboid with distantly trilobed…………….Pueraria phasioloides 9a.Leaflets obovate or ovate ………………………….…………. Desmodium Abrus precatorius L. (K705) Fig. 4; Alysicarpus vaginalis (L.) DC. (K606); Cajanus scarabaeoides (L.) du Petit Thou (K650); Dalbergia sissoo Roxb. (K635); Derris scandens (Roxb.) Benth. (K687); Desmodium gangeticum (L.) DC. (K662); D. triflorum (L.) DC. (K675); Flemingia chappar Buch.-Ham. ex Benth. (K673); Pongamia pinnata (L.) Pierre (K637); Pueraria phasioloides (Roxb.) Benth. (K638); Tephrosia purpurea (L.) Pers. (K690). 170 Vascular plants diversity in Danga forest of Balurghat Desmodium : Key to species: 1.Leaves unifoliolate with stipels; plant suberect ……………..D. gangeticum 1a.Leaves trifoliolate without stipels; prostrate plant ……………D. triflorum

SAPINDACEAE 1.Trees; leaves imparipinnate, leaflets entire ……..Erioglossum rubiginosum 1a.Climber with tendrils; leaves 2-ternate, leaflets dentate...Cardiospermum helicacabum Cardiospermum helicacabum L. (K615); Erioglossum rubiginosum (Roxb.) Bl. (K430).

RUTACEAE 1.Small or large tree; flowers lax ………………………………………..……2 1a.Shrub; flowers densely aggregated ……………………. Glycosmis arborea 2.Plants aromatic, small tree, without thorns...... Murraya 2a.Plants non aromatic with thorns …………………………..Aegle marmelos Aegle marmelos (L.) Corr. (K730); Glycosmis arborea (Roxb.) DC. (K722); Murraya koenigii (L.) Sprengel (K731); M. paniculata (L.) Jack (K752).

Murraya : Key to the species : 1.Leaf lets 3-8; a bushy small tree …………………………...…M. paniculata 1a.Leaf lets 10-20; a small spreading tree …………………………M. koenigii

MELIACEAE 1.Leaves 2-3-pinnate; ovary 5-locular …………………...... …Melia azadirach 1a.Leaves unipinnate; ovary 3-locular.…………………….Azadirachta indica Azadirachta indica A. Juss. (K612); Melia azadirach L. (K758).

ANACARDIACEAE Mangifera indica L. (K771).

POLYGALACEAE Polygala chinensis L. (K888).

OLACACEAE Olax scandens Roxb. (K759) Fig. 5.

RHAMNACEAE Zizyphus oenoplia (L.) Mill. (K741) Fig. 6; Z. mauritiana Lamk. (K745).

Zizyphus : Key to the species: 1.Lianas; fruits when ripe black …………………………...……….Z. oenoplia 1a. Tree; fruits when ripe orange ………………………………..Z. mauritiana

VITACEAE 1.Leaves simple; inflorescence modified to tendrils….…Ampelocissus latifolia 1a.Leaves compound; tendrils directly from stem ……..…………….Cayratia Ampelocissus latifolia (Panch.) Roxb. (K744); Cayratia pedata (Panch.) Roxb. (K757); C.trifolia (L.) Domin. (K646).

Cayratia: Key to the species: 1.Leaflets 3……………………………………...... …C. trifolia 1a.Leaflets pedately 7 ……………………………………....………..C. pedata Parasuram Kamilya 171 LEEACEAE Leea indica (N.Burman) Merril (K626); L. rubra Bl. (K616). Leea : Key to species : 1.Undershrubs; flowers greenish-white ……………………………….L.indica 1a.Herbs; flowers red ……………………………………………….…L. rubra

APIACEAE Centella asiatica Urb. (K785).

ASTERACEAE 1.Climbers with opposite leaves always ………….....……….Mikania cordata 1a. Erect or prostrate herbs with opposite or alternate leaves………………....2 2.Erect herbs with radical leaves growing just above the soil surface ……...... 4 2a. Erect or prostrate herbs leaves cauline ……………………………………3 4.Leaves runcinate-pinnatifid; involucre cylindrical…….……Yongia japonica 4a. Leaves toothed; involucre compressed………………Elephantopus scaber 3.Flower heads yellow ……………………………..…………………………5 3a. Flower heads white or whitish-blue ……………………………………….6 5. Leaves toothed, simple ……………………………………………………..7 5a.Leaves pinnatifid ………………………………...Grangea maderaspatana 7.Involucre ovoid or oblong; calyx limb 2-3-toothed……Synedrella nodiflora 7a. Involucre hemispherical; calyx limb obsolete …………Centipeda minima 6.Heads discoid ……………………………………………………………….8 6a. Heads radiate ………………………………….…………Eclipta prostrata 8.Leaves opposite; pappus bristly ……………..………..Ageratum conyzoides 8a. Leaves alternate; pappus hairy …………………………..Vernonia cineria

Ageratum conyzoides L. (K667); Centipeda minima (L.) A. Braum & Aschers (K681); Eclipta prostrata L. (K645); Elephantopus scaber L. (K670); Grangea maderaspatana (L.) Poir (K682); Mikania cordata (Burm.f.) Roxb. (K786); Synedrella nodiflora (L.) Gaertn. (K776); Vernonia cineria Less (K657); Yongia japonica (L.) DC. (K669).

RUBIACEAE 1.Trees ………………………………………………………………………...2 1a. Herbs or shrubs ……………………………………………………………3 2.Flowers in dense heads………………………………………………………4 2a.Flowers in terminal or axillary drooping spikes….Hymenodictyon exelsum 4.Stipules lanceolate, caducous; flowers yellow…...….Anthocephalus indicus 4a.Stipules connate, sheathing persistant; flowers yellow...Morinda angustifolia 3.Prickly shrub …………………………………………..……Meyna laxiflora 3a. Herbs ……………………………………………………………………....5 5.Prostrate herbs ………………………………………………………………6 5a. Erect or suberect herbs ……………………………………………………7 6.Flowers tetramerous; upper surface of stem reddish & angles sharp ………………………………………………………....Spermacoce articularis 6a. Flowers pentamerous; stem green, angles not sharp………Dentella repens 7.Flowers densely verticelled at node ………..……………Mitracarpus hirtus 7a. Flowers not densely verticelled at node ……………………………..……8 8.Flowers pink or lilac, subsessile on elongating branches of terminal spikes …………………………………………………………….Knoxia sumatrensis 8a.Flowers white, pedicelled, axillary solitary or corymb ……..…Oldenlandia 172 Vascular plants diversity in Danga forest of Balurghat Anthocephalus indicus Rich (K729); Dentella repens Forst (K728). Hymenodictyon exelsum Wall. (K693); Knoxia sumatrensis (Retz.) DC. (K601); Meyna laxiflora Robyns. (K627); Mitracarpus hirtus (L.) DC. (K653); Morinda angustifolia Roxb. (K788) Fig. 7; Oldenlandia corymbosa L. (K664); O. diffusa (Willd.) Roxb. (K787); Spermacoce articularis L.f. (K790).

Oldenlandia : Key to the species : 1.Leaf margin flat; flowers 2-6 in long peduncled umbellate cymes…………………………………………………………… O. corymbosa 1a.Leaf margin recurved; flowers solitary on short peduncle ……...O. diffusa

APOCYNACEAE PLUMERIOIDE 1.Small shrubs; two ovaries connate but distinct; fruit drupe-like not follicle ………………………………………………………..…..Rauwolfia serpentina 1a.Shrub or small tree or large tree; two ovaries free; fruit a pair of follicle …2 2.Leaves digitately whorled, lateral veins almost parallel…………Alstonia scholaris 2a.Leaves opposite-superposed or decussate, lateral veins not parallel ………3 3.Large shrubs or small tree; seeds not comose ……………Tabernaemontana divaricata 3a. Large tree; seeds comose ……………….…….Holarrhena antidysenterica Alstonia scholaris R.Br. (K789); Holarrhena antidysenterica Wall. (K656); Rauwolfia serpentina (L.) Benth ex Kurz. (K720); Tabernaemontana divaricata (L.) R.Br. (K726).

APOCYNOIDEAE Ichnocarpus frutescens (L.) R.Br. (K716) Fig. 8.

PERIPLOCOIDEAE 1.Leaves thick , shining with parallel lateral nerves united to form an intramarginal ring; corolla lobes contorted in bud …….Cryptolepis buchanani 1a.Leaves comparatively thin, non shining and lateral nerves not parallel; corolla lobes valvate in bud …………….……………….Hemidesmus indicus

Cryptolepis buchanani Roem. & Schult. (K641) Fig. 9; Hemidesmus indicus (L.) R.Br. (K724)

ASCLEPIADOIDEAE Dregea volubilis Benth. (K679).

SOLANACEAE Solanum indicum L. (K693); S. torvum Swartz. (K683); S. verbasifolium L. (K632); S. viarum Dunal (K963)

Solanum : Key to species : 1.Small tree like; leaves entire; spines absent………...……..S. verbascifolium 1a. Shrub or undershrub; leaves lobed; spines present …….…………………2 2.Spines abundant; fruits with whitish streaks………………………S. viarum 2a.Spines few; fruits without whitish-streaks.…………………………….….3 3.Flowers blue ………………….…………………………..……… S. indicum 3a. Flowers white …………………………………………….…...... S. torvum

CONVOLVULACEAE 1.Erect shrubs with milky latex……………………………..Ipomoea fistulosa Parasuram Kamilya 173 1a.Prostrate herbs without milky latex ………………………………………..2 2.Style 2, free, each 2-branched; stigmas subclavate...Evolvulus nummularius 2a.Style 1, entire; stigma with 2-globose lobes ……………………..Merremia

Evolvulus nummularius (L.) L. (K890); Ipomoea fistulosa Martius ex Choisy (K867); Merremia chryseides Hallier f. (K873): M. emarginata Hallier f. (K801); M. hederacea Hallier f. (K809); M. tridentata Hallier f. (K739).

Merremia : Key to the species : 1.Buds long, conical, acute; leaves 3-toothed at base…………….M. tridentata 1a.Buds short, globose, obtuse; leaves entire or crenate or 3-loabed …………2 2.Leaves acute; ovate-cordate ………………………………………………...3 2a.Leaves obtuse, small, reniform,crenate ……………..………M. emarginata 3.Leaves glabrous, usually basally 3-lobed; corolla funnel shaped……....M. chryseides 3a.Leaves sparingly pubescent, all entire; corolla subcampanulate ……M. hederacea

BORAGINACEAE Heliotropium indicum L. (K753); H. strigosum Willd. (K765). Heliotropium : Key to species : 1.Fruits divided into four 1-seeded nut lets; plants erect; lamina ovate…..H. indicum 1a.Fruits divided into two 1-seeded pyrenes; plants prostrate; lamina lanceolate to linear- lanceolate ……………………………………H. strigosum

SCROPHULARIACEAE 1.Flowers always regular, tetramerous, leaves in whorl of 3-4……….Scoparia dulcis 1a.Flowers always irregular; pentamerous; leaves either in basal whorl or opposite- decussate ……………………………………………….……………2 2.Submerged leaves multifid and aerial leaves entire or serrate...…Limnophila 2a.Semiaqatic or terrestrial plants having leaves entire or serrate ……………3 3.Plants prostrate; calyx quincuncial, enlarging with the fruits; flowers yellow …………………………………………………....…..Mecardonia procumbens 3a.Plants erect or suberect; calyx valvate, connate totally or partially; flowers white or whitish-tinge…………………………………………….……………4 4.Basal leaves radical, spreading, long-petioled, spathulate, upper leaves alternate; calyx wide campanulate ……………………….…….Mazus pumilus 4a.Leaves throughout opposite-decussate; calyx covering the fruit…Lindernia

Limnophila heterophylla (Roxburgh) Bentham (K775); L. indica (Linnaeus) Druce (K777); Lindernia ciliata (Colsm.) Penn. (K718); L. crustacea F. Muell (K727); L. hyssopoides (Linnaeus) Haines (K629); L. nummularifolia (D. Don) Wettstein (K642); L. parviflora (Roxburgh) Haines (K715); L. procumbens (Kroker) Borbas (K784); L. viscosa (Hornemann) Boldingh (K607); Mazus pumilus (Burm.f.) Steenis (K725); Mecardonia procumbens (Miller) Small (K764); Scoparia dulcis Linnaeus (K723).

Limnophila : Key to the species : 1.Few upper leaves opposite, remaining alternate; flowers long-pedicelled ...... L. indica 1a.All upper leaves opposite; flowers sessile……..……………L. heterophylla

Lindernia : Key to the species : 1.Sepals united to above the middle …………………………………..………2 174 Vascular plants diversity in Danga forest of Balurghat 1a.Sepals free almost to the base or if united then to below the middle …...…4 2.Capsules linear-cylindrical, ± twice as long as the sepals……………….…..3 2a.Capsules ellipsoid to oblong-ovoid, not or slightly longer than the sepals …… …… ……………………………………………………..………………....L. crustacea 3.Leaf blade elliptical-ovate to oblong, the margin terminating in spines……………………………………………………………….…L. ciliata 3a.Leaf blade ovate-orbicular or orbicular, teeth along the margin not terminating in spines ……………………………...………..L. nummularifolia 4.Stamens 4, all bearing well-developed anthers …………….……………….6 4a.Stamens 2 or 4, when 4 then 2 staminodal .……………………………..…5 5.Leaf blades palmately 3 or 5 nerved (appearing parallel-nerved from the base to the tip of the blade) …………………………..……….L. hyssopioides 5a.Leaf blades pinnately nerved or 1-nerved……………………..L. parviflora 6.Atleast the upper most flowers in terminal racemes with each flowers subtended by a scale-like bract …………………………….………..L. viscosa 6a.All flowers solitatry in the axils of leaf like bracts………….L. procumbens

ACANTHACEAE

1.Perfect stamens 4…………………………………….………………………2 1a.Perfect stamens 2 …………………………………………………………..3 2.Capsule linear or linear-oblong; bracteoles small, narrow or obsolete…………………………….……………………………...Hemigraphis 2a.Capsule clavate; bracteoles large, leafy.….….….Dipteracanthus prostratus 3.Obsolete or reduced stamens or staminodes present …………….………….4 3a.Obsolete or reduced stamens or staminodes absent ………………………..5 4.Corolla distinctly 2-lipped; calyx lobes 5…………………..…….Hygrophila 4a.Corolla subequally 5-lobed; calyx lobes 4 ………………..Barleria cristata 5.Seeds not supported on retinacula; bracts herbaceous.……………..Nelsonia canescens 5a.Seeds supported on retinacula; bracts otherwise ………….……………….6 6.Ovules 2 in each cell ………………………………………………………..7 6a.Ovules 4-6 in each cell ….………………….…….Andrographis paniculata 7.Placentas separating elastically from valves from the base upward; flowers on one sided spikes ……………………………………….….Rungia pectinata 7a.Placentas not separating elastically from valves; flowers all sides the spike or panicle …………………………………………………………………….8 8.Anther-cells, at least the lower one spurred or minutely apiculate at base …… …… ……………….……………………………………….……..Justicia japonica 8a.Anther-cells muticous …………………………… Peristrophe bicalyculata . Andrographis paniculata (Burm.f.) Wall. ex Nees (K763); Barleria cristata L. (K623); Dipteracanthus prostratus (Poir.) Nees (K737); Hemigraphis hirta (Vehl) T. Anders. H. latebrosa (Roth) Nees (K757); Hygrophila difformis (L.f.) Blume (K733); H. polysperma (Roxb.) T. Anders. (K602); H. schulli (Hamilt.) M.R. & S.M. Almeida (K721); Justicia japonica Thunb. (K631); Nelsonia canescens (Lam.) Spreng. (K903); Peristrophe bicalyculata (Retz.) Nees (K834): Rungia pectinata (L.) Nees (K804).

Hemigraphis : Key to species : 1.Corolla tubular-ventricose; longer filaments glabrous in their upper half …H. hirta Parasuram Kamilya 175 1a.Corolla funnel shaped; longer filaments densely bearded in their upper half … …… ……………………….……………………………………………..H. latebrosa

Hygrophila : Key to species : 1.Unarmed; calyx teeth 5; seeds more than 8 per fruit ………………………..2 1a.Armed; calyx-lobes 4; seeds 4-8 per fruit ………………………..H. schulli 2.Leaves pinnatified or sharply crenate-serrate; plants glandlur and aromatic …… ………………………………………………………….………..H. difformis 2a.Leaves entire; plants eglandular, not aromatic………………H. polysperma

VERBENACEAE 1. Small or large trees………………………………………………….……..2 1a. Shrub or herbs ……………………………………………………………..3 2. Corolla regular; stamens isomerous; equal ……………….Tectona grandis 2a. Corolla 2-lipped; stamens didymus ………………………Premna latifolia 3. Plants prostrate herb; leaves spathulate ……….…………..Phyla nodiflora 3a. Plants erect or suberect shrub ……………………………………….…….4 4. Plants aromatic ……………………………………….……Lippia javanica 4a. Plants non-aromatic ……….………………………………...Clerodendrum

Clerodendrum indicum (L.) Ktze. (K875); C. viscosum Vent.(K852); Lippia javanica (Burm.f.) Sprenge. (K734); Phyla nodifloria (L.) Greene (K751); Premna latifolia Roxb. (K778); Tectona grandis L.f. (K748).

Clerodendrum : Key to species : 1.Leaves linear-oblong; corolla narrowly funnel shaped.…….……..C. indicum 1a.Leaves broadly ovate; corolla irregular salver-shaped……...…..C. viscosum

LILIOPSIDA COLCHICACEAE Gloriosa superba L. (K887).

ORCHIDACEAE 1.Anther single ……………………………………….……………………….2 1a.Anther 2, each with 1perfect cell….…………….Habenaria commelinifolia 2.Epiphytic orchid; pollinia waxy …………………..………..Vanda tessellata 2a.Terrestrial orchid; pollinia not waxy.……..…………Zeuxine strareumatica

Habenaria commelinifolia Wall. ex Lindl. (K893); Vanda tessellata (Roxb.) Lodd. ex G. Don. (K815); Zeuxine straeumatica (L.) Schl. (K829).

PONTEDERIACEAE 1.Flowers sessile; perianth strongly zygomorphic, posterior tepals with a discolourous blotch ……………….…………..………….Eichhornia crassipes 1a.Flowers distinctly pedicelled; perianth actinomprphic, posterior tepals not with a discolourous bloch..…………….…………….……Monochoria hastata

Eichhornia crassipes (Mart.) Solms (K889); Monochoria hastata (L.) Solms. (K823). 176 Vascular plants diversity in Danga forest of Balurghat SMILACACEAE Smilax zeylanica DC. (K732)

DIOSCOREACEAE Dioscorea belophylla Voigt ex Haines (K614); D. bulbifera L. (K743); D. pentaphylla L. (K792).

Dioscorea : Key to the species : 1.Leaves palmately 5 or 3 foliolate……………………....…….D. pentaphylla 1a.Leaves simple ……………………………………………………………...2 2.Outer perianth segments linear; male spikes slender, drooping; seeds not winged ……………………………………………….…………….D. bulbifera 2a.Outer parianth-segments not linear; male spikes stiffly spreading; seeds winged …………………………………………………………...D. belophylla

ZINGIBERACEAE Curcuma aromatica Salisb. (K860).

COSTACEAE Costus speciosus (Koen.) Smith (K846).

COMMELINACEAE 1.Inflorescence a cymose panicle or a cluster of 1-6 flowers; bracts small, not spathaceous …………………………………………….… Murdania nodiflora 1a.Inflorescence a cyme enclosed in large conduplicate spathaceous bract …… …… ………...………………………………………….…….…..Commelina Commelina beghalensis L. (K754); C. paludosa Bl. (K857); Murdania nodiflora (L.) Brenan (K820).

Commelina : Key to the species : 1.Ovule 1 in each cell or chamber; scrambling or scandent herbs…C. peludosa 1a.Ovules 2 in each cell or locule at the anterior part while 1 in each cell or locule in posterior part of the ovary; decumbent or ascending herbs …………………………………………………..……………..C. benghalensis

CYPERACEAE 1.Flowering glumes distichous ………………………………………………..2 1a.Flowering glumes spirally arranged ……………….……….…..Fimbristylis 2.Style 2-fid .……………………………….………………………….Kyllinga 2a.Style 3-fid ………………………………………………….…..…..Cyperus

Cyperus compressus L. (K817); C. corymbosus Rottb. (K891); C.rotundus L. (K836); Fimbristylis aestivalis (Retz.) Vahl (K814); F.eragrostis (Nees & Meyen ex Nees ) Hance (K854); Kyllinga brevifolia Rottb. (K929); K. triceps Rottb. (K910).

Cyperus : Key to the species : 1.Rachilla of spikelets not prominently winged …………..……C. compressus 1a.Rachilla of spikelets distinctly winged ………………………………….…2 2.Leaves short, rarely half as long as the stem ………………….C.corymbosus 2a.Leaves long, always more than half as long as stem …………...C. rotundus Parasuram Kamilya 177 Fimbristylis : Key to the species : 1.Lower glumes distichous, upper ones irregularly spiral …..…....F.eragrostis 1a. Glumes all regularly spiral………………………………..……F. aestivalis

Kyllinga : Key to the species : 1.Rhizome creeping, elongated ………………………….…….….K. brevifolia 1a. Rhizome very short ……………………………………..….…….K. triceps

POACEAE 1.Spikeleta many flowered …………………………………………………....2 1a. Spikelets one or two flowered i,e. glumes 6 or fewer……………………..5 2.Secondery branches of the inflorescence on all sides of the primary axis ….3 2a. Secondary branches distichously arranged on the primary ……………….4 3.Spikelets almost sessile …………….………………….Leptochloa chinensis 3a. Spikelets distinctly stacked …………………………….Eragrostis tenella 4.Inflorescence axis terminated by spikelets ………….………Eleusine indica 4a.Inflorescence axis terminated by mucro………Dactyloctenium aegypticum 5.Spikelets one flowered, …………………………………………………….6 5a. Spikelets 2-flowered ………………………………………………………7 6.Terminal pair of branches digitate; not floating herb….Digitaria adscendens 6a.Terminal pair of branches not digitate; floating herbs ………..Hygroryza aristata 7.Spikelets awned ……………………………………Chrysopogon aciculatus 7a. Spikelets never awned ……………………………………………………8 8.Spikelets seated on a whorl of bristles ……………………….Setaria glauca 8a. Spikelets not seated on a whorl of bristles ……………………………....9 9.Inflorescence with white silky hairs ……….………...….Imperata cylindrica 9a. Inflorescence not silky ………………………………………………….10 10.Inner lemma white and firmest …………………...…….Brachiaria reptans 10a.Outer glume firmest…….…………………...………..Vetiveria zizanoides

Chrysopogon aciculatus Trin. (K908); Brachiaria reptans (L.) Gardner (K869); Dactyloctenium aegypticum (L.) Beauv. (K830); Digitaria adscendens (H.B.K.) Henrard.(K813); Eleusine indica Gaertn. (K849); Eragrostis tenella Roem. & Schult. (K803); Hygroryza aristata Nees (K906); Imperata cylindrica (L.) Beauv. (K904); Setaria glauca Beauv. (K901); Vetiveria zizanoides (L.) Nash. (K848).

HYDROCHARITACEAE 1.Rhizomaceous stem; leaves petiolated , parallel cross veins among the primary veins …… ………………………… ...... …………...….Ottelia alismoides 1a.Stem not rhizomaceous; leaves sessile, parallel cross veins absent ….……2 2.Leaves whorled in each node, ovate- oblanceolate, spines absent … …… ………………...... ………………………………….….Hydrilla verticillata 2a.Leaves radical, narrowly strap-shaped, margin often with spines …… ……… …………...... ……………………………………...Vallisneria spiralis

Hydrilla verticillata (L.f.) Royle (K913); Ottelia alismoides (Wall.) Dandy (K923); Vallisneria spiralis L. (K918).

ALISMATACEAE Sagittaria : Key to the species : 1.Leaf blade emergent, sagittate; sepals in fruit reflexed…… …… ………… …. 178 Vascular plants diversity in Danga forest of Balurghat …………………………………………………………S. sagittifolia ssp. leucopetala 1a. Leaf blade floating, heart shaped; …………..…..S. guanensis ssp. lappula

Sagittaria guanensis ssp. lappula (D.Don) Bogin (K839) Fig. 10; S. sagittifolia ssp leucopetala (Miquel) Hartong (K826).

APONOGETONACEAE Aponogeton appendiculatus H. Bruggen (K828).

POTAMOGETONACEAE Potamogeton crispus L. (K916); P.mucronatus Presl. (K916). Potamageton : Key to the species: 1.Leaves sessile, semi-amplexicaul at base …………...…………………P. crispus 1a.Leaves distinctly petiolate, truncate or cuneate at base ……...P. mucronatus

DISCUSSION Among tree taxa Barringtonia acutangula, Bombax ceiba, Eucalyptus globulus, Gelonium multiflorum, Holarrhena antidysenterica, Hymenodictyon exelsum, Lagerstroemia speciosa, Shorea robusta, Syzygium cumini and Terminalia arjuna are common. However, dominant frequency is seen in Lagerstroemia speciosa, Tectona grandis and Terminalia arjuna. These tree taxa are of plantation types according to forest Range officer. The distribution of Barringtonia acutangula among which Helminthostachys zeylanica and Vetiveria zizanoides along the forest margin of East-South side create attention to any botanist to predict the presence of riverbed in the past. Different lianas taxa like, Abrus precatorius, Caesalpinia bonduc, Cryptolepis buchanani, Capparis zeylanica, Ampelocissus latifolia, Tiliacora racemosa, Ichnocarpus frutescens etc make bushy forest canopy here and there. The endangered taxon, Helminthostachys zeylanica (Fig. 11 & 12) is growing luxuriantly among the roots of Vetiveria zizanoides in about 10 acres area in a density of 2.42 as reported by the present author in 2010, in ENVIS Newsletter, BSI, indicates possibly some kind of mycorrhizal association for future research. Many shrubs or small trees like Tabernaemontana divaricata, Murraya koenigi, Flacourtia ramontchi, Meyna laxiflora, Zizyphus oenoplia etc. are scattered throughout the forest floor. Tabernaemontana divaricata and Murraya koenigii, although cultivated taxa, but grow here possibly getting safe undisturbed natural residence. Only one rare tree species Bischofia javanica is growing in the North-East corner of the forest. Besides Helminthostachys some other pteridophytes are Cyclosorus, Cheilanthes, Diplazium, Selaginella, Lygodium, Asplenium, Dryopteris and Ophioglossum. Some aquatic flora of the families Alismataceae, Aponogetonaceae, Hydrocharitaceae, Pontederiaceae and Potamogetonaceae are growing in moist and waterlogged ditches within the forest. An uncommon aquatic taxon like Sagittaria guanensis ssp. lappula is growing in little water body inside forest. Thus this mixed seminatural vegetational pocket zone that is under the control of Raiganj Forest Division needs special protection for endangered taxon like Helminthostachys zeylanica and other ecologically interested taxa by concerned authorities. Acknowledgements The author is greatful to Dr.Gouri Das, Dept of Botany, Balurghat College, Dr. Chandra Ghosh, Dept. of Botany Gour Mahavidyalaya, Malda for supply some correct author’s citation and encouragement. The author is further indebted to Ajoy Das, Project Assistant of Biodiversity Project, West Bengal, for typing the research paper. Parasuram Kamilya 179

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7 8 9

10 11 12 Fig. 1. Polyalthia suberosa; Fig. 2. Tiliacora racemosa; Fig. 3. Capparis zeylanica; Fig. 4. Abrus precatorius; Fig. 5. Olax scandens; Fig. 6. Zizyphus oenoplia; Fig. 7. Morinda angustifolia; Fig. 8. Ichnocarpus frutescens; Fig. 9. Cryptolepis buchanani; Fig. 10. Sagittaria guanensis ssp. lappula; Fig. 11. Habitat of Helminthostachys zeylanica; Fig. 12. a plant of Helminthostachys zeylanica with bifur- cated spike

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