Suaeda torreyana Wats is a tall shrub in the family Chenopodiaceae and is distributed in riparian or palustrian habitats in Great Basin Desert. Suaeda torreyana produced brown and black seeds with other morphological variations. Germination responses of brown and black seeds to various temperature and salinity also differ showing a physiological dimorphism in addition to morphological dimorphism. Germination of black and brown seeds inhibited with increase in salinity, however, no brown seeds germinated above 600 mM NaCl whereas, 40% germination was recorded in brown seeds at 1000 mM NaCl treatment. Rate of germination of brown seeds was much higher as compared to black seeds. All brown seeds at low salinity treatments were germinated with in 48 hours of treatment. Brown and black seed also showed a remarkable difference in their response to various thermoperiods. Brown seeds prefer hot alternating temperature regimes while black seeds prefer cold for germination.

Key words: Suaeda torreyana, germination, halophyte, salinity, Great Basin Desert, temperature