International Research Journal of Biological Sciences ___________________________________ ISSN 2278-3202Vol. 4(2), 21-27, February (2015) Int. Res. J. Biological Sci. International Science Congress Association 21 Diversity, Uses and Origin of Invasive Alien Plants in Dhenkanal district of Odisha, India NayakSandeep KumarandSatapathy Kunja Bihari P.G. Department of Botany, Utkal University, Vani Vihar, Bhubaneswar, 751004, Odisha, INDIA Available online at: www.isca.in, www.isca.me Received 13th October 2014, revised 4th December 2014, accepted 11th January 2015Abstract An exhaustive floristic survey was carried out during 2013-2014 in the Dhenkanal district of Odisha state to assess the diversity, nativity and uses of invasive alien plants. From the study it was found that 131 species with 97 genera and under 39 different families were invasive alien plants. Analysis of habit revealed that the herbs were dominant with 114 species (87.65%) followed by shrubs (12), trees (02) and climbers (03). And the dominant family was Asteraceae with 25 (19.23%) species followed by Amaranthaceae (08), Euphorbiaceae (08), Caesalpiniaceae (07), Convolvulaceae (07), Fabaceae (06), Mimosaceae (05), Poaceae (05), Solanaceae (05), Asclepiadaceae (04), Cleomaceae (04), Tiliaceae (04), Cyperaceae (03), Lamiaceae (03). These families included most invasive species, such as Chromolaena odorata, Lantana camara, Hyptis suaveolens, Ageratum conyzoides, Parthenium hysterophorus, Eichhornia crassipes, Alternanthera philoxeroides, and others. The dominance of Asteraceae species among all IAPS found in this region was resulted due to higher potential for adaptability and rapid growth. It was found from the literature that different native places of IAPS of Dhenkanal district were Tropical America (83), Tropical Africa (12), Tropical South America (9), Europe (4), Brazil (3), Tropical north America (3), West Indies (3), Mediterranean (3), Tropical Central South America (2), Tropical Central America (1), Tropical East Africa (1), Peru (1), Mascarene Islands (1), Mexico (1), Temperate South America (1), Madagascar (1),West Asia (1), Afghanistan (1) and Tropical West Asia (1). From the interaction with local people and literature survey it was found that IAPS were used as medicine (70), fuel (3), ornamental (6), rope making (2) and leafy vegetable (4). Keywords: Dhenkanal, diversity, exotic, invasive alien plant species (IAPS).Introduction Invasive alien plant species are the plants whose introduction or spread threatens the environment, the agricultural economy, human health and biodiversity of a region. Biological invasion by alien species is recognized as an important component of anthropogenic biodiversity change in global level, which has a significant impact on economy, species diversity, and change in the invaded ecosystem where it was naturalized. TheIntroduction of IAPS can occur accidentally or by means of import for some purposes and they are able to escape from the captive field and large scale spread over a region is the result. Most often introduction of exotic species into new habitats is taken place for certain economic reasons like to cater demand of paper industries and forage requirement and in many cases it can be linked to the consequences of economic activities in a large scale as a result, in several countries about 20% of total plant species are now become non-indigenous. The mobile nature of our society, intentional trade and transport are helping the rapid spread of IAPS. In case of many islands, the exotic plant species are going to be more than 50% of total flora due to inflow of people from main land and aggressive development of tourism sector. Invasive alien plants are become a problem in every continent of the globe, causing a huge economic loss in agricultural sector, decline of species diversity, acute respiratory illness and encroachment to every type of ecosystem. In the country like South Africa, 161 species of IAPS are causing serious problem in regional level and the status of IAPS indicates the spread in large area with ability to dominate the vast landmass in just a few years. The situation in United States is also no better and about 125-150 billion US Dollar is lost in each year due to foreign pests and weeds. India is a biodiversity rich country with different climate, soil, topography and vegetation which encourages different alien plants to proliferate extensively. According to the inventory of invasive alien plant species, 173 species are identified as invasive alien and regional documentation of IAPS in Dhenkanal district of Odisha has not been done so far, so the current study was conducted to find out the diversity, uses and origin of IAPS in the district. Material and Methods Study area: Dhenkanal is one of the landlocked central district of Odisha with 4452 Sq. Km geographical area lying between Longitude 85° 58' to 86° 2' East and Latitude 20° 29' to 21° 11' North. It is surrounded by Keonjhar, Cuttack, Jajpur and Angul districts at north, south, east and west respectively. The second Research Journal of Biological Sciences _______________________________________________________ ISSN 2278-3202 Vol. 4(2), 21-27, February (2015) Int. Res. J. Biological Sci. International Science Congress Association 22 largest river of Odisha, Brahmani is flowing through the district making it suitable for wide range of flora. This district experiences climate of hot and dry sub humid type with 1696 mm average annual rainfall. The temperature ranges from 19.6°C to 33.3°C with relative humidity ranging from 31 to 88%. Out of the total geographical area of 4452 Sq. km., forest area comprises 1737.62 Sq. Km. Methods: The study was conducted during 2012-14 to compile a comprehensive list of invasive alien plant species and interaction with local inhabitants were made to collect information regarding the various uses of Invasive Alien plant Species (IAPS) by the local populace. Plant samples were collected and photographed from their natural habitat including agricultural field, water bodies, marshes, pathways and adjoining area of forest patches in the district and identified by referring “Flora of Orissa” and other available literatures. Collected plant specimens were processed to prepare herbaria by following the standard procedure (BSI) and were deposited in the Herbarium of P.G. Department of Botany, Utkal University, Bhubaneswar, Odisha. After an extensive review of literature, history, diversity, sources and behaviour of exotic invasive plant species were analyzed 9-21, and the list of invasive alien plant species of Dhenkanal district was prepared. The nativity of species were represented based on the reports published by several workers22-31. Results and Discussion The exhaustive floristic survey of Dhenkanal district revealed that a total of 131 species (table-1) belonging to 97 genera and under 39 different families were invasive alien plant species with 114 species (89.3%) (Table 3) were herb which followed by shrubs (12), trees (02) and climbers (02). Asteraceae was the dominant family with 25 (19.23%) species (Table 4) followed by Amaranthacae (08), Euphorbiaceae (08), Caesalpiniaceae (07), Convolvulaceae (07), Fabaceae (06), Mimosaceae (05), Poaceae (05), Solanaceae (05), Asclepiadaceae (04). (Table 4). These top ten families contributed 80 species with a proportion of 77.67%. Most of the species were found growing in all kinds of ecosystems like forests, agricultural fields, waste and fallow lands, gardens and road-sides. Genera-wise quantitative analysis showed that Cassia with 7 species followed by Ipomoea (6 species), Alternanthera (4 species), Cleome (3 species), Corchorus (3 species), Ludwigia (3 species) and other genera contain less than three. The predominance of the family Asteraceae species in invasive categories shows the high impact on this region. The extensive survey on floristic composition of the region indicated that about half of total IAPS were growing luxuriantly and became threat to endemic flora and gradually their populations were occupying the habitats of endemic flora. The history of IAPS in this region revealed that many species were introduced for economic purpose like timber, ornamental, and green coverage of barren land and some were migrated to this region by transport of food grains from other regions. Climatic conditions of the region became suitable for them and they showed rapid proliferation to spread all over the district. Most of the weeds, both aquatic and terrestrial, were reported in the locality for a very long period of time. Among the 131 species, 27 species were identified as invaders with prolific growth in wetland, and some of these were Aeschynomene americana, Alternanthera paronychioides, Alternenthera philoxeroides Bidens pilosa, Casia alata, Cyperus difformis, Cyperus iria, Echinochloa colona, Echinochloa crusgalli, Eclipta prostrata, Eichhornia crassipes, Gnaphalium pensylvanicum, Gnaphalium polycaulon, Grangea maderaspatana, Ipomoea carnea, Ludwigia adscendes, Ludwigia octovlavis, Ludwigia perennis, Monocharia vaginalis, Pistia stratiotes, Portulaca quadrifida, Saccharum spontaneum, Salvania molesta, Sesbania bispinosa, Sonchus asper, and Typha angustata (table-1). These species were located in all wetlands of the district and were in the complete state of naturalization. In forest ecosystem, Chromolena odorata Lantana camara and Hyptis suaveolens were found in dominant stage whereas along road side Parthenium hysterophorus and Sida acuta were well established and in unused land, Argemone mexicana,Cassia tora, Cleome viscosa, Chamaesyce hirta,Croton bonplandianum,Eclipta prostrata, Ipomoea carnea, Mimosa pudica, Tridax procumbens were occupied most of the land cover. Besides the negative impact of IAPS on endemic flora and agriculture, some of them were found to be useful to local people. Prosopsis juliflora,Borassusflabellifer and Leucaena leucocephala were used as timber and several invasive alien herbs like Argemone mexicana, Casia tora,Cleome viscosa,Crotonbonplandianum,Eclipta prostrata, Mimosa pudica,Tridax procumbens, etc. were used as medicine for different ailments. Alternanthera philoxeroides and Portulaca oleraceawere used as leafy vegetables by local tribes, table-1. The people of the area were preferring some of the alien tree species for firewood requirement due to their first growth nature. It was also found from literature that different native places of IAPS of Dhenkanal district (table-2) were Tropical America (83), Tropical Africa (12), Tropical South America (9), Europe (4), Brazil (3), Tropical north America (3), West Indies (3), Mediterranean (3), Tropical Central South America (2), Tropical Central America (1), Tropical East Africa (1), Peru (1), Mascarene Island (1), Mexico (1), Temperate South America (1), Madagascar (1), West Asia (1), Afghanistan (1) and Tropical West Asia (1) Table-1 Research Journal of Biological Sciences _______________________________________________________ ISSN 2278-3202 Vol. 4(2), 21-27, February (2015) Int. Res. J. Biological Sci. International Science Congress Association 23 List of invasive alien plant species found in Dhenkanal district of Odisha Sl. No. Species Family Habit Use Nativity 1 Acacia mearnsii D e Willd. Mimosaceae Tree M, Fuel Trop. South America 2 Acanthospermum hispidum DC. Asteraceae Herb M Brazil 3 Aerva javanica (Burm.f.) Juss.ex Schult. Amaranthaceae Herb M Trop. Ameri ca 4 Aeschynomene americana L. Fabaceae Herb Co Trop. America 5 Ageratum conyzoides L. Asteraceae Herb M Trop. America 6 Alternanthera paronychioides St. Hil Amaranthaceae Herb M Trop. America 7 Alternanthera philoxeroides (Mart.) Griseb. Amaranthaceae Herb V Trop. America 8 Alternanthera pungens Kunth Amaranthaceae Herb M, C Trop. America 9 Alternanthera tenella Colla Amaranthaceae Herb V Trop. America 10 Antigonon leptopus Hook. and Arn. Polygonaceae Climber M Trop. America 11 Argemone mexicana L.Papaveraceae Herb A, M Trop. Central and South America 12 Asclepias curassavica L. Asclepiadaceae Herb C Trop. America 13 Asphodelus tenuifolius Cav. Liliaceae Herb Nk Trop. America 14 Bidens pilosa L. Asteraceae Herb M Trop. America 15 Blainvillea ac mella (L.) Philipson Asteraceae Herb C Trop. America 16 Blumea eriantha DC. Asteraceae Herb C Trop. America 17 Blumea lacera (Burm.f.) DC. Asteraceae Herb M Trop. America 18 Blumea obliqua (L.) Druce Asteraceae Herb C Trop. America 19 Borassus flabelli fer L. Arecaceae Tree H, Fd Trop. Africa 20 Calotropis gigantea R.Br. Asclepiadaceae Shrub M Trop. Africa 21 Calotropis procera (Ait.) R.Br. Asclepiadaceae Shrub M Trop. Africa 22 Cardamine trichocarpa Hochst. ex A.Rich. Brassicaceae Herb Nk Trop. Amer ica 23 Cardiospermum halicacabum L. Sapindaceae Climber M Trop. America 24 Cassia absus L. Caesalpiniaceae Herb M Trop. America 25 Cassia alata L. Caesalpiniaceae Shrub M West Indies 26 Cassia hirsuta L. Caesalpiniaceae Herb M Trop. America 27 Cassia obtusifolia L. Caesalpiniaceae Herb M Trop. America 28 Cassia occidentalis L. Caesalpiniaceae Herb C Trop. South America 29 Cassia pumila Lam. Caesalpiniaceae Herb C Trop. America 30 Cassia tora L. Caesalpiniaceae Herb M, Fu Trop. South America 31 Cath aranthus pusillus (Murr.) G. Don Apocynaceae Herb C Trop. America 32 Celosia argentea L. Amaranthaceae Herb C, M Trop. Africa 33 Chamaesyce hirta (L.) Millsp. Euphorbiaceae Herb M Trop. America 34 Chamaesyce indica (Lam.) Croizat Euphorbiaceae Herb M Tr op. South America 35 Chloris barbata Sw. Poaceae Herb Fo Trop. America 36 Chromolaena odorata (L.) King and Robins. Asteraceae Herb Nk Trop. America 37 Chrozophora rottleri (Geis.) Juss. Euphorbiaceae Herb Nk Trop. Africa 38 Cleome gynandra L. Cleomace ae Herb M Trop. America 39 Cleome monophylla L. Cleomaceae Herb M Trop. Africa 40 Cleome rutidosperma DC. Cleomaceae Herb M Trop. America 41 Cleome viscosa L. Cleomaceae Herb M Trop. America 42 Conyza bipinnatifida Wall. Asteraceae Herb C Trop. America 43 Corchorus aestuans L. Tiliaceae Herb M Trop. America 44 Corchorus tridens L . Tiliaceae Herb V Trop. Africa 45 Corchorus trilocularis L. Tiliaceae Herb C Trop. Africa 46 Crassocephalum crepidioides (Benth.) Moore Asteraceae Herb C Trop. America 47 Crotalaria pallida Ait. Fabaceae Herb C Trop. America 48 Crotalaria retusa L. Fabaceae Herb C Trop. America 49 Croton bonplandianus Boill.Euphorbiaceae Herb C Temperate South America 50 Cryptostegia grandiflora R.Br. Asclepiadaceae Herb M Madagascar 5 1 Cuscuta chinensis Lam. Cuscutaceae Herb M Mediterranean Research Journal of Biological Sciences _______________________________________________________ ISSN 2278-3202 Vol. 4(2), 21-27, February (2015) Int. Res. J. Biological Sci. International Science Congress Association 24 Sl. No. Species Family Habit Use Nativity 52 Cuscuta reflexa Roxb. Cuscutaceae Herb M Mediterranean 53 Cyperus difformis L. Cyperaceae Herb C Trop. America 54. Cyperus iria L. Cyperaceae Herb N Trop. America 55 Datura innoxia Mill. Sola naceae Shrub M Trop. America 56 Datura metel L . Solanaceae Shrub M Trop. America 57 Dicoma tomentosa Cass. Asteraceae Herb M Trop. Africa 58 Digera muricata (L.) Mart. Amaranthaceae Herb V SW Asia 59 Dinebra retroflexa (Vahl) Panz. Poaceae Herb Nk Trop . America 60 Echinochloa colona (L.) Link Poaceae Herb M Trop. South America 61 Echinochloa crusgalli (L.) Beauv. Poaceae Herb A Trop. South America 62 Echinops echinatus Roxb. Asteraceae Herb M Afghanistan 63 Eclipta prostrata (L.) Mant. Asteraceae He rb M Trop. America 64 Eichhornia crassipes (Mart.) Solms - Loub. Pontederiaceae Herb Co, WT Trop. America 65 Emilia sonchifolia (L.) DC. Asteraceae Herb C Trop. America 66 Euphorbia cyathophora Murr. Euphorbiaceae Herb O Trop. America 67 Euphorbia hetero phylla L. Euphorbiaceae Herb M Trop. America 68 Evolvulus nummularius (L.) L. Convolvulaceae Herb C Trop. America 69 Flaveria trinervia (Spreng.) C. Mohr.Asteraceae Herb M Trop. Central America 70 Fuirena ciliaris (L.) Roxb. Cyperaceae Herb Nk Trop. Am erica 71 Galinosoga parviflora Cav. Asteraceae Herb M Trop. America 72 Gnaphalium pensylvanicum Willd. Asteraceae Herb Nk Trop. America 73 Gnaphalium polycaulon Pers. Asteraceae Herb Nk Trop. America 74 Gomphrena serrata L. Amaranthaceae Herb Nk Trop. America 75 Grangea maderaspatana (L.) Poir. Asteraceae Herb M Trop. South America 76 Hyptis suaveolens (L.) Poit. Lamiaceae Herb Ch Trop. America 77 Impatiens balsamina L. Balsaminaceae Herb O Trop. America 78. Indigofera linnae Ali Fabaceae Herb Nk Tr op. Africa 79 Ipomoea carnea Jacq. Convolvulaceae Shrub M Trop. America 80 Ipomoea eriocarpa R.Br. Convolvulaceae Herb M Trop. Africa 81 Ipomoea hederifolia L. Convolvulaceae Herb C Trop. America 82 Ipomoea obscura (L.) Ker - Gawl. Convolvulaceae Herb N k Trop. America 83 Ipomoea pes - tigridis L. Convolvulaceae Herb M Trop. East Africa 84 Ipomoea quamoclit L. Convolvulaceae Herb O Trop. America 85 Lantana camara L. Verbenaceae Herb Bsk, O Trop. America 86 Leonotis nepetiifolia (L.) R.Br. Lamiaceae Her b M Trop. Africa 87 Leucaena leucocephala (Lam.) de Wit Mimosaceae Herb Fo, wd Trop. America 88 Ludwigia adscendes (L.) Hara Onagraceae Herb M Trop. America 89 Ludwigia octovlavis (Jacq.) Raven Onagraceae Herb M Trop. Africa 90 Ludwigia perennis L. On agraceae Herb M Trop. Africa 91 Malachra capitata (L.) L. Malvaceae Herb M Trop. America 92 Martynia annua L. Martyniaceae Herb M Trop. America 93 Mecardonia procumbens (Mill.) Small Scrophulariaceae Herb Nk Trop. North America 94 Melilotus alba Desv. Fabaceae Herb Nk Europe 95 Melochia corchorifolia L. Sterculiaceae Herb M Tropical America 96 Mikania micrantha Kunth Asteraceae Climber C Trop. America 97 Mimosa pigra L. Mimosaceae Shrub M Trop. North America 98 Mimosa pudica L. Mimosaceae Herb M Bra zil 99 Mirabilis jalapa L. Nyctaginaceae Herb O Peru 100 Monochoria vaginalis (Burm.f.) Presl. Pontederiaceae Herb Nk Trop. America 101 Nicotiana plumbaginifolia Viv. Solanaceae Herb Nk Trop. America 102 Ocimum canum Sims Lamiaceae Herb M Trop. America 103 Opuntia stricta (Haw.) Haw. Cactaceae Herb Nk Trop. America 104 Oxalis corniculata L. Oxalidaceae Herb M Europe Research Journal of Biological Sciences _______________________________________________________ ISSN 2278-3202 Vol. 4(2), 21-27, February (2015) Int. Res. J. Biological Sci. International Science Congress Association 25 Sl. No. Species Family Habit Use Nativity 105 Parthenium hysterophorus L. Asteraceae Herb A Trop. North America 106 Passiflora foetida L. Passifloraceae Herb O, M Trop. South America 107 Pedalium murex L. Pedaliaceae Herb M Trop. America 108 Peperomia pellucida (L.) Kunth Piperaceae Herb Nk Trop. South America 109 Phyllanthus tenellus Roxb. Euphorbiaceae Herb Nk Mascarene Islands 110 Pistia stratiotes L. Araceae Herb M Trop. America 111 Portulaca oleracea L. Portulacaceae Herb M,V Trop. South America 112 Portulaca quadrifida L. Portulacaceae Herb M Trop. America 113 Prosopis juliflora (Sw.) DC. Mimosaceae Shrub Wd Mexico 114 Saccharum spontaneum L. Poaceae Herb Rope Making Trop. West Asia 115 Salvinia molesta D. S. Mitch. Salviniaceae Herb Nk Brazil 116 Scoparia dulcis L. Scrophulariaceae Herb M Trop. America 117 Sesbania bispinosa (Jacq.) Wight Fabaceae Shrub Rope Making Trop. America 118 Sida acuta Burm.f. Malv aceae Herb M Trop. America 119 Solanum torvum Sw. Solanaceae Shrub M West Indies 120 Solanum viarum Dunal Solanaceae Herb C Trop. America 121 Sonchus asper Hill Asteraceae Herb M Mediterranean 122 Spermacoce hispida L. Rubiaceae Herb Nk Trop. America 123 Stachytarpheta jamaicensis (L.) Vahl Verbenaceae Herb M Trop. America 124 Synadenium grantii Hook. f. Euphorbiaceae Shrub M Trop. America 125 Synedrella nodiflora (L.) Gaertn. Asteraceae Herb M West Indies 126 Tribulus terrestris L. Zygophyllaceae Herb M Trop. America 127 Tridax procumbens L.Asteraceae Herb M Trop. Central America 128 Triumfetta rhomboidea Jacq. Tiliaceae Herb Ht Trop. America 129 Typha angustata Bory. and Choub. Typhaceae Herb M Trop. America 130 Urena lobata L. Malvaceae Shru b M Trop. Africa 131 Xanthium indicum L. Asteraceae Herb M, Fu Trop. America Abbreviations : A- Adulteration in food grains, Fu- Fuel, Bsk- Basket and mat making , C- Biologically active Compound, Co- Compost, Fo- Fodder, Ht- Hut making, Hf- Hand held Fan, M-Medicine, Nk- Not known, O-Ornamental, V-Vegetable, WT- Waste Water Treatment, Wd- Wood Figure-1 Nativity of invasive alien plant species in Dhenkanal district of Odisha Research Journal of Biological Sciences _______________________________________________________ ISSN 2278-3202 Vol. 4(2), 21-27, February (2015) Int. Res. J. Biological Sci. International Science Congress Association 26 Figure-2 Habit of invasive alien plant species in Dhenkanal district of Odisha Figure-3 Family wise distribution of 10 top families of invasive alien plants of Dhenkanal district of OdishaConclusion Invasive alien plant species diversity in Dhenkanal district of Odisha is one of the major threat for endemic flora due to their aggressive colonizing ability and adaptability. Their populations are increasing rapidly and started encroaching crop fields, which is a major concern for local people, as it directly affect the agricultural economy, Hence eradication of IAPS from this region is needed in an urgent basis. But the eradication procedure requires a huge financial provision which is not so easy for this region. So awareness among local people is only possible method to get rid of IAPS. Besides this, utilization of hidden medicinal potential can make IAPS beneficial to the people of the region. Moreover the effect of IAPS in economy, biodiversity and human health is yet to be assessed in a broad spectrum in national and regional level. The current study can provide the status of IAPS in the region for further study and assessment. Table-2 Regions of Nativity of invasive alien plant species in Dhenkanal district of Odisha Sl. No. Region of Nativity No. of Species 1 Tropical America 82 2 Tropical Africa 12 3 Tropical South America 09 4 Europe 04 5 Brazil 03 6 Tropical north America 03 7 West Indies 03 8 Mediterranean 03 9 Tropical Central South America 02 10 Tropical East Africa 01 11 Peru 01 12 Mascarene Island 01 13 Mexico 01 14 Temperate South America 01 15 Madagascar 01 16 South West Asia 01 17 Afghanistan 01 18 West Tropical Asia 01 19 Tropical Central America 01 Table-3 Habit of invasive alien plant species in Dhenkanal district of OdishaSl. No. Habit No. of Species 1 Herb 114 2 Shrub 12 3 Tree 2 4 Climber 3 Table-4 Family wise distribution of 10 top families of invasive alien plants of Dhenkanal district of OdishaSl. No. Family No. Species 1 Asteraceae 25 2 Amaranthaceae 8 3 Euphorbiaceae 8 4 Caesalpiniaceae 7 5 Convolvulaceae 6 6 Fabaceae 5 7 Mimosaceae 5 8 Poaceae 5 9 Solanaceae 5 10 Asclepiadaceae 4 Research Journal of Biological Sciences _______________________________________________________ ISSN 2278-3202 Vol. 4(2), 21-27, February (2015) Int. Res. J. Biological Sci. International Science Congress Association 27 References 1.Williamson M., Biological invasions. Chapman and Hall, London. (1996) 2.Levine S.A.,Analysis of risk for invasions and control program, Biological Invasion : A Global Perspective, SCOPE 37(eds. Drake J. A. et al.,), John Wiley, Chichester, UK, 425-435 (1989) 3.Mc Neely J.A., Invasive species : A costly catastrophe for native biodiversity, Land Use Water Resour Res, , 1–10 (2001)4.Randall J.M. and Marinelli J.,Invasive Plants : Weeds of the Global Garden, Brooklyn Botanic Garden, Brooklyn, New York (1997) 5.Henderson L., Plant invaders of Southern Africa, Agricultural Research Council, Pretoria, (1995)6.McNeely J.A., Mooney H.A., Neville L.E., Schei P. and Waage J.K., A Global Strategy on Invasive Alien Species, IUCN Gland, Switzerland, and Cambridge, U.K., in collaboration with the Global Invasive Species Program, (2001)7.Reddy C.S., Catalogue of Invasive Alien Flora of India, Life Science Journal, 2), 84-89 (2008)8.Saxena H.O. and Brahmam M., The Flora of Orissa, Vol. I-IV, Orissa Forest Development Corporation, Bhubaneswar (1996)9.Mooney H.A. and Drake J.A., The ecology of biological invasions, Environment, 29(5), 12 (1987)10.Heywood V., Patterns, Extents, and Modes of Invasions by Terrestrial Plants, In: Drake J, et al (eds.), Biological Invasions : A Global Perspective, Wiley, NY., 31-60(1989)11.Cox G.W., Alien Species in North America and Hawaii: Impacts on Natural Ecosystems, Island Press, Washington, D.C., (1999) 12.D’Antonio C.M. and Vitousek P.M., Biological invasions by exotic grasses: the grass/fire cycle and global change, Annual Review of Ecology and Systematics,23, 63–87 (1992)13.Drake J.A., Mooney H.A., Castri F. di, Groves H., Kruger F.J., Rejmanek M. and Williamson M., (eds). Biological Invasion : A global Prospective, John Wiley, Chichester, UK (1989)14.Huxel G.R., Rapid displacement of native species by invasive species: effect of hybridization, Biological Conservation, 89, 143-52 (1999) 15.Jenkins P.T., Trade and exotic species introductions, 229-235, In Sandlund, O.T., Schei, P.J. and Viken, A. (eds.), Invasive Species and Biodiversity Management, Kluwer, Dordrecht, the Netherlands, (1999) 16.Lonsdale W.M., Global patterns of plant invasions and the concept of invisibility, Ecology,80(5), 1522-1536 (1999)17.Mooney H.A., A global strategy for dealing with alien invasive species. Invasive species and Biodiversity management (ed. Sandlund OT, Schei PJ and Viken A),Kluwer Academic Publishers, London 24, (1999)18.Almeilla I.D. and Freitas H., The exotic and invasive flora of Portugal, Bot Complutensis,25, 317-27 (2001) 19.Cowie R., Does the public care about species loss?, A glimpse into the public’s flunking, Conservation Biology in Practice,2(3), 28 -9 (2001) 20.McNeely J.A., Mooney H.A., Neville. L.E., Schei P.J. and Waage J.K. (eds), Global strategy on invasivealien species, IUCN, Gland, Switzerland, (2001) 21.Reddy C.S., Bagyanarayana G., Reddy K.N. and Raju V.S., Invasive Alien Flora of India, National Biological Information Infrastructure, USGS, USA (2008)22.VavilovN.I.,The origin, variation, immunity and breeding of cultivated plants, Chron Bot,13, 1–364 (1951) 23.Matthew K.M., Exotic flora of Kodaikanal and Palni hills, Rec Bot Surv India,20(1), 1-241 (1969)24.Maheswari J.K. and Paul S.R., The exotic flora of Ranchi, J Bombay Nat Hist. Soc,72(1), 158–88 (1975) 25.Nayar M.P., Changing Patterns of the Indian Flora, Bulletin of Botanical Survey of India, 19(1-4) 145-155 (1977) 26.Hajra P.K. and Das B.K., Vegetation of Gangtok with Special Reference to Alien Plants, India Forums, 107, 554-566 (1982)27.Sharma B.D., Exotic Flora of Allahabad, Botanical Survey of India, Dehra Dun, (1984) 28.Saxena K.G., Biological Invasion in the Indian Sub Continent : Review of Invasion by Plants, In: P.S. Ramakrishnan, Ed., Ecology of Biological Invasion in the Tropics, International Scientific Publications, New Delhi, 53-73 (1991) 29.Pandey R.P. and Parmar P.J., The exotic flora of Rajasthan, J Econ Tax Bot,18(1), 105-21 (1994) 30.Reddy C.S. and RajuV.S., Additions to the weed flora of Andhra Pradesh, India. J Econ Taxon Bot., 26, 195–198 (2002)31.Reddy C.S. and Reddy K.N., Cassia rotundifolia Pers. (Caesalpiniaceae) : A new record for India, J Econ Tax Bot, 28, 73-4 (2004)