What is salinity ? What are halophytes?

Salt stress is a adverse stimulus caused by presence of excess of inorganic salts. Therefore, the salt content of the substratum is also called salinity. The common ions having high concentration in saline habitats are Na+, CL, Ca2+, SO4 2-, and CO3 2-.
Plants growing in high salt habitats are called halophytes. There are three types of halophytes- salts excluders, salts excretors and salts accumulators.