Biological World

    Economic Importance of Lichens Lichens have little direct economic value. Even in a few cases where they are used commercially, as in perfumery and medicine, their importance is not widely recognized. However lichens do have considerable indirect importance in the primary food chain for grazing animals and invertebrates including insects, and their usefulness to nature is quite considerable, Lichens as food Lichens have been used as food in times of scarcity. They contain lichenin, a carbohydrate allied to starch, Cetraria islandica Cladonia spp, Evernia prunastri and Lecanorae sculenta are used as food. In India, the genus Parmelia and members of the family Usneaceae are used as food by the natives. Lichens growing on soil may contain bitter irritating acids, especially fumarprotocetraric acid, which while not poisonous, must be removed by boiling in soda.  Lichens will, of course, never be utilized as food source by man on a large scale. Although their nutritive va...

Sevoke (also spelled Sevok or Sivok) is a tiny town near Siliguri in the Darjeeling district of West Bengal state, India, on the border with the state of Sikkim. It is the county seat of the Darjeeling district. Sevoke, which is a part of the Dooars, is located on the banks of the River Teesta. The town is crossed by two bridges, the Coronation Road Bridge and the Sevoke Railway Bridge, which span the River Teesta. Several army and Border Security Force (BSF) camps are located in the region. This region contains the Mahananda Wildlife Sanctuary, which is open to the public. National Highway 10 goes through the town and links it to the cities of Gangtok and Siliguri on the Tibetan Plateau. It begins in Sevoke at the Coronation Bridge and ends in Guwahati, where it is known as National Highway 17. Different kinds of angioperms, pteridophytes and bryophytes are found in the regions