Flora of assam

1. Flora of Assam Submitted by Silvinus Clisson Pragash

2. Flora of Assam Assam General Characteristics Assam , one of the biodiversity hotspots occupies a special place in North-eastern India located between 24° 44 ' N to 27° 45'N Latitude and 89° 41'E to 96° 02'E Longitude, covering 2.4% of the geographical area of the country. The annual rainfall ranges between 305 cm. max . to 178 cm. min. with an average of 211.76 cm. The temperature recorded in summer is 37 ° C max. and 18 ° C min. and 26 ° C max. and 7 ° C min. in winter, with an average humidity of 83.00 Forest Status & Bio Diversity Estimation of Assam Total recorded forest area of the state is 28,748 sq.km . out of which 359 sq. km. come under water bodies and covers 32% of the total geographical area. On the other hand forest & tree cover is 36.67% of geographical areas including homestead forestland . Pattern of rainfall configuration of grounds are the factors controlling the distribution of plants in to the types of forest association. The state consists of two valleys- the Brahmaputra and the Barak, separated by range of comparatively low hills . The Barak or Surama valley receives direct N.W. Monsoon ; due to the presence of steep hills it receives a good precipitation in comparison to the Brahmaputra valley, which is much less open to the monsoon winds.

3. Flora of Assam Assam General Characteristics Grass lands occur in the deciduous tracts and also in the riparian areas of the Brahmaputra and it's tributaries. The length of the Brahmaputra river in Assam is 640 km. & length of the Barak river is 225 km. and there are 121 drainage systems or tributaries in both the Brahmaputra & the Barak. The river Brahmaputra covers 23,3000 sq.km . under its drainage system in India. T he major forest types of Assam are 1. Tropical wet evergreen. 2. Tropical semi evergreen. 3. Tropical moist deciduous. 4. Sub-tropical broad leaved hill . 5. Sub-tropical pine and littoral. 6. Swamp forests . This types can be broadly taken under the following categories namely 1. Evergreen. 2. Deciduous. 3. Swamp forest. 4. Grass lands.

4. Flora of Assam Assam General Characteristics

5. Flora of Assam Assam General Characteristics 1. Evergreen Evergreen areas are under Lakhimpur, Dhemaji, Dibrugarh , Sibsagar, Tinsukia, Cachar and extend as far as up to Panchnadi in the north bank and Golaghat district. The dominent families are Dilleniaceae , Anonaceae , Clusiaceae , Magnoliaceae , Fabaceae , Myrtaceae, Styraceae , Ebenaceae , Myristicaceae , Lauraceae , Euphorbiaceae , Fagaceae, Arecaceae & Poaceae, and Dipterocarpaceae are also characterised by storied formation of a forest and presence of various climbers . 2. Deciduous. Deciduous forests lie mainly in the sal tracts. Dhubri,Kokrajhar , Goalpara , Bongaigaon,Chirang , Baksa , Nalbari & Udalguri come under this area . Associates of sal are Lagerstroemia perviflora , Kydia calycina , Schima Wallichi , Careya arborea , Gmelina arborea , Cassia fistula, Albizzia lucida . A.odoratissima , Millusa velutina , Stereospermum chelonoides etc . 3. Swamp Forest Swamp areas are generally beels or low lying areas, abandoned river channels etc. In these areas following species are common: Crataeva lophosperma , Eugenia species, Duabanga grandiflora , Te rminalia myriocarpa , Lagerstroemia flos-regina , Trewia nudiflora , Ficus pyriformes etc . and also grasses like Hygrorhiza aristata , Vossia procera , Panicum proliferum , Phragmities communis & P.karka , Arundo donax etc . Aquatic plants such as Nymphaeceae , Lamnaceae , Alismaceae , Naiadaceae , Eriocauleceae , Cyperaceae etc. are common.

6. Flora of Assam Assam General Characteristics 4. Grass Lands Grass lands are of two types- one in the riperian belt, the other is in low rainfall areas. In riperian areas, Saccharum , Anthistena , Erianthus , Arundo , Phragmities.etc are common and on the other hand in low rainfall areas Imperata arundinaceae , Aptuda varia , Andropogon jwarancusa , Nardus contortus , Setaria glauca etc. are common.

7. Flora of Assam

8. Flora of Assam Exotics  Assam Lemon: An unique product of Assam with a high percentage of Vitamin C (10 mg.) besides Vitamin B (0.02 mg.), Niacin (0.1) per 100 gm. Extractable oil content of the peel is around 0.8% and can be used in the cosmetic industry. Hatkora : An exclusive export item belonging to the citrus family. Peel is used for tenderizing meat and enhancing flavour in culinary dishes. Orchids: Of the 925 varieties available in India, over 600 can be grown in Assam. Around 200 varieties are unique to this region of which 60% are ornamental in nature. Aromatic Rice ( Joha Rice): Quality comparable with any popular aromatic rice in the world. Bhut Jalakia ( Capsicum Chinensis   Jacq .) : Hottest chilli on earth with Scovelli Heat Unit (SHG) of 10,41,047.

9. Flora of Assam

10. Flora of Assam Assam is traditionally rich in horticultural production due to its diverse and unique agro-climatic condition which is conductive for growing wide range of horticultural crops like various fruits, vegetables, flowers, spices, nuts, tuber crops and medicinal and aromatic plants. Horticultural crops occupy about 15% of the gross cultivated area of Assam and annually produces more than 14.0 lakh MT of fruits, 39.0 lakh MT of vegetables and 2.0 lakh MT of spices besides nut crops, flowers and medicinal & aromatic plants thus contributing significantly towards food and nutritional security of the State. In spite of having all these inherent potentiality, commercialisation of horticulture sector in Assam is not yet achieved.

11. Flora of Assam

12. Flora of Assam Tea of Assam - Camellia sinensis  var.  assamica The state of Assam is the world's largest tea-growing region, lying on either side of the Brahmaputra  River. The tropical climate contributes to Assam's unique malty taste, a feature for which this tea is well known. Though  Assam  generally denotes the distinctive black teas from Assam, the region produces smaller quantities of green and white teas as well with their own distinctive characteristics.  Historically, Assam has been the second commercial tea production region after southern China. Southern China and Assam are the only two regions in the world with native tea plants. Assam tea revolutionized tea drinking habits in the 19th century since the tea, produced from a different variety of the tea plant, yielded a different kind of tea . The tea plant is grown in the lowlands of Assam, unlike  Darjeeling  and Nilgiris, which are grown in the highlands. The Assam tea bush grows in a lowland region, in the valley of the Brahmaputra River, an area of clay soil rich in nutrients of the floodplain. The climate varies between a cool, arid winter and a hot, humid rainy season—conditions ideal for it. Because of its lengthy growing season and generous rainfall, Assam is one of the most prolific tea-producing regions in the world. Each year, the tea estates of Assam collectively yield approximately 1.5 million pounds (680,400 kg) of tea. Assam tea is generally harvested twice, in a “first flush” and a “second flush.” The first flush is picked during late March. The second flush, harvested later, is the more prized “tippy tea,” named thus for the gold tips that appear on the leaves. This second flush, tippy tea, is sweeter and more full-bodied and is generally considered superior to the first flush tea. The leaves of the Assam tea bush are dark green and glossy and fairly wide compared to those of the Chinese tea plant. The bush produces delicate white blossoms.

13. Flora of Assam Bamboos in Assam: Bamboos have gained considerable importance in the socio-economic life of people in Assam for the variety of uses they cater to. Altogether 38 naturally growing species of bamboo are recorded in Assam of which Bamboosa masrtersei is restricted in distribution to Dibrugarh district. Bamboosa cacharensis , Dinochlora compactiflora , D.india are restricted to Barak Valley. Chimnobabusa griffithiana and Oxetenanthera parviflora are restricted in distribution to N.C.Hills . Bambusa rangaensis grows wild in the Ranga R.F. of Lakhimpur district. Bamboosua vulgaris is the introduced species cultivated throughout Assam as ornamental plant. Bambusa jaintiana and Melocanna arundiana are the species reported only from Assam. There are no exclusive bamboo forest in the plains of Assam, bamboo grooves are found mostly along the edge of Reserve Forests. But pure bamboo forests occur in N.C Hills and Karbi Anglong districts predominated with Melocanna baccifera and Chimnobambusa griffithiana . Bamboo is cultivated widely in Assam and every household grows bamboo in its bari land. Commonly cultivated species are Bambusa balcooa ( Bhaluka bamboo), Bambusa tulda ( Jati bamboo), Malocanna bacciferra ( Muli bamboo), Dendrocalamus hamiltonii (Koko bamboo) and Dendrocalamus giganteus ( Mokalm bamboo).

14. Flora of Assam Bamboos in Assam: Bamboos have gained considerable importance in the socio-economic life of people in Assam for the variety of uses they cater to. Altogether 38 naturally growing species of bamboo are recorded in Assam of which Bamboosa masrtersei is restricted in distribution to Dibrugarh district. Bamboosa cacharensis , Dinochlora compactiflora , D.india are restricted to Barak Valley. Chimnobabusa griffithiana and Oxetenanthera parviflora are restricted in distribution to N.C.Hills . Bambusa rangaensis grows wild in the Ranga R.F. of Lakhimpur district. Bamboosua vulgaris is the introduced species cultivated throughout Assam as ornamental plant. Bambusa jaintiana and Melocanna arundiana are the species reported only from Assam. There are no exclusive bamboo forest in the plains of Assam, bamboo grooves are found mostly along the edge of Reserve Forests. But pure bamboo forests occur in N.C Hills and Karbi Anglong districts predominated with Melocanna baccifera and Chimnobambusa griffithiana . Bamboo is cultivated widely in Assam and every household grows bamboo in its bari land. Commonly cultivated species are Bambusa balcooa ( Bhaluka bamboo), Bambusa tulda ( Jati bamboo), Malocanna bacciferra ( Muli bamboo), Dendrocalamus hamiltonii (Koko bamboo) and Dendrocalamus giganteus ( Mokalm bamboo).