{'fraction_non_alphanumeric': 0.018726591760299626, 'fraction_numerical': 0.013857677902621723, 'mean_word_length': 4.868864468864468, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Diversity of the Family Leguminosae in Koch Bihar District, West Bengal

Introduction: Legume a fascinating group of flowering plants belongs to the family Leguminosae or Fabaceae is deserve special attention as they play vital role both in human welfare as well as in ecological aspect. The district of Koch Bihar of West Bengal state has no account about the diversity of leguminous plants and their utilization by the ethnic and local peoples which initiates to undertake the present work. Methods: Extensive field surveys in different parts of Koch Bihar in different seasons of five consecutive years were conducted to record the legumes of the district and their uses following the standard methods. Voucher specimens were processed and identified by using relevant literature and matching with herbarium specimens. Result and Discussion: It is evident from the present study that the legumes of Koch Bihar district are represented by 81 species under 36 genera with Desmodium as dominant genus having 9 species. Maximum number of species have been recorded in the subfamily Faboideae (47 species) followed by Caesalpinioideae(18 species) and Mimosoideae(16 species). Among the 81 species of legumes there are 29 species of herbs, 28 species of trees, 16species of shrubs and 8species of climbers. It is interesting to note that a good number of legumes are exotic in origin and American elements are more dominant among the alien species. During the field study utilization of legume by the major ethnic communities (viz. Kheria, Oraon, Rabha, Rajbanshi, and Santal) and the local inhabitants of the district have also been recorded. It reveals that 31 species under 24 genera which is about 38% of the legume flora of the district are used in various purposes and several species have more than one kind of use. Conclusions: Destruction of the habitat and the anthropogenic interferences are identified as the basic causes for the loss of diversity of legumes of the district. Similarly, acculturation is the reason for extinction of traditional knowledge regarding herbal therapy.


INTRODUCTION
The family Leguminosae (Fabaceae) commonly known as legume or bean family is the third largest family among the flowering plants which is represented by 19,500 species under 770 genera 1 and is cosmopolitan in distribution. Human society is benefited by this group of plants as they are not only the source of pulses, fodder, oil seeds, medicines, timber etc but they also increase soil fertility by fixing atmospheric Nitrogen. This family is traditionally divided into three sub-families namely Mimosoideae, Caesalpinioideae and Faboideae (=Papilionoideae). Hutchinson 2 had recognized these three sub-families as independent families-Mimosaceae, Caesalpiniaceae and Fabaceae. This view was followed by Cronquist 3 , Dahlgren 4 and others. But the present trend is to consider the above stated three sub-families under broadly circumscribed Leguminosae or Fabaceae. Morphological characters as well as rbcL sequence data support this view 5 . Takhtajan 6 , Thorne 7 and APGIV 8 also recognized the similar treatment .Recently the Legume Phylogeny Working reflect the diversity of leguminous plants of the district. The present work is therefore, undertaken to record the species diversity of the legumes of Koch Bihar district of West Bengal. Not only that an endeavor has also been made to record the local uses of such leguminous plants by the local ethnic and rural peoples of the district which will be helpful to preserve the indigenous knowledge of the ethnic communities of the district.
The district of Koch Bihar is situated under Jalpaiguri division of the state of West Bengal in between 26 o 32 ' 46 " to 25 o 57 ' 57 " N latitude and 89 o 52 ' 00 " to 88 o 45 ' 02 " E longitude and covering an area of 3,386 sq Km. The district is surrounded by Alipurduar district of West Bengal in northern and most part of Western side. The Southern boundary of the district is very much indented and is formed by the Rangpur district of Bangladesh. The eastern boundary is formed by the Goalpara district of Assam. The entire district is intersected by six river systems, namely Tista system, Jaldhaka system, Torsha system, Kalzani system, Raidak system and Gadadhar system. The soil of Koch Bihar district is alluvial type of rather recent origin and is mainly sandy loam type. The climate of the district is characterized by high humid atmosphere and abundant rain with the temperature being seldom excessive. The district receives an average rainfall of 320.1cm. Rajbanshi is the major ethnic community which constitute about 40% population of the district. The other ethnic groups are Kheria, Oraon, Rabha and Santal. Most of them are village dwellers and depend on plant and plant products to maintain their life and livelihood.

MATERIALS AND METHODS
The present work is based on screening of herbarium specimens deposited at Central National Herbarium, Howrah and extensive survey conducted in different areas of Koch Bihar district in different seasons of five consecutive years. Plant specimens were collected from the field and preserved following the guidelines of Lawrence 16 and Jain & Rao 17 . Local uses of the plants and vernacular names (if any) were procured from the ethnic medicine men and elderly knowledgeable persons of the villages through interview. The information was collected following Jain 18,19,20 and Pal & Jain 21 with some minor changes wherever required. Correct identity and updated nomenclature of the collected plant specimens were established with the help of published literature and also comparing with the authentic herbarium specimens of Central National Herbarium (CAL).

Under shrub
Jul-Jan.           During the present study uses of leguminous plants by the ethnic communities and rural peoples of the district has also been recorded. The results shows that 31 species of legumes under 24 genera are used for various purposes which are about 38% of the legume flora of the district and several species have more than one kind of uses. The collected information shows that plants and plant parts of 11 species are edible, 20 species have medicinal uses, 2 species are used as fodder, woods of 3 species are used in constructions and making household articles and 6 species have miscellaneous uses. A total of 69 uses have been recorded during the present study and it has been noted that leaves of the legumes are used in maximum occasion (18) followed by stem &twigs (14) and roots &seeds (09).

CONCLUSION
The present study concludes that the Leguminosae or Fabaceae is the most dominant and diversified family which constitutes about 10% of the total Angiospermic flora of the district. But the rapid urbanization and increase in population causes serious damage to the habitats of these plants.
Much damage to the forest vegetation is being done by the cattle grazing. Grazing animals on one hand browse the tree seedlings and on the other hand trampling the soil and seedlings. Therefore, soil become compact and become unsuitable for the growth of the plants. Anthropogenic interference like extraction of "catechu" gum from Acacia catechu, peeling of barks for preparation of medicines and careless and illegal cutting and lopping from the plants for the purpose of fodder and firewood are the causes of the loss of species diversity. Similarly, extensive collection of useful seeds, fruits, roots etc. from plants like -Abrus precatorius, Derris indica, Butea monosperma, Mucuna pruriens etc. effects the natural regeneration of population of the species. On the other hand the indigenous knowledge especially the uses of the herbal drugs are in threat due to modernization of the society and loss of interest among the young generation of ethnic and rural peoples about the traditional healing methods. It is, therefore, an urgent need to protect the plants to save the diversity of leguminous flora as well as the ethnic culture of the district.