this may be out of place but i need help on find a plant that would survive in the harsh Martian environment. lets just say that we have already made it so that the atmospheric pressure is almost the same as earths. also if this is in the wrong area please direct me to the right area.

I thought the plants were to make the atmospheric pressure higher.

First off, scratch anything needing insects for pollination...

 

Second, consider conditions, cold, fairly arid, alkaline soil, possibly on the salty side.

 

Third, look for areas on earth where those conditions occur.

 

Fourth, investigate native flora of those regions.

 

Fifth, evaluate candidates for vigor, water retention/economy, and spread of leaves for making most of meager solar energy density.

 

Sixth, test! Try growing candidates in approximately similar atmospheric, soil and illumination conditions.