Greenhouse for the underwater cultivation of terrestrial plant species as well as an underwater cultivation assembly using it

Assembly for underwater cultivation of terrestrial plant species comprising a greenhouse (10) for the underwater cultivation of terrestrial plant species wherein said greenhouse comprises a balloon (11) adapted to being filled with air in an underwater environment (50), said balloon (11) comprising a lower aperture (12) for lower access to said balloon (11), said balloon (11) being made from material that is impermeable to water and permeable to light, said balloon (11) comprising at least one inner support shelf (17) having at least one seedbed (53) and means for restraining (14) said balloon (11) to a floor (51) of an aquatic basin said balloon (11) comprising at a top portion opposite to said lower access aperture (12), a first vent valve (15) for releasing air inside said balloon (11), wherein said balloon (11) also comprises a second adjustment valve (16) for adjusting a level of a water-air interface (52) inside said balloon (11), said second adjustment valve (16) being integrated in a surface of said balloon above a surface of the water (11) substantially at the height of said lower access aperture (12) and said at least one inner support shelf (17) being arranged at a higher height with respect to said second adjustment valve (16) wherein at least one water-tight container (20) comprising a box-shaped body (21) fitted with a cover (22) that is at least partially removable and an interface (23) for connecting to underwater immersion equipment.