PLANT

In the Cosmic Era, the present-day United Nations funded the idea of constructing new space colonies originally as manufacturing and research facilities. Known as PLANTs (Productive Location Ally on Nexus Technology) these hourglass shaped colonies were primarily manned by Coordinators. Over time, they became a haven and eventually the permanent home of the vast majority of the Coordinator population, fleeing persecution and when the war begin, they became an independent nation. The PLANTs are divided into 12 groups known as "Cities," each one named for a month of the Roman Calendar (i.e. Aprilius, Junius). It should be noted that apparently, in CE 73, the signification of the acronym 'PLANT' has been changed to PEOPLE LIBERATION ACTING NATION OF TECHNOLOGY.

The government of the PLANT cities is the PLANT Supreme Council on Aprilius One which was originally formed to deal with the UN directorate of PLANT-sponsored nations, and their military is Zodiac Alliance of Freedom Treaty or ZAFT for short. The PLANTs are described as one nation by some characters, but they are in fact several different nations (each PLANT city can be considered an independent nation) united in their common heritage and the need for protection. The word "PLANT" is actually sometimes used to referred to all the PLANTs as a whole (again as if they were a single nation), and the term ZAFT is also used to (incorrectly) describe the PLANTs.

Each City originally incorporated ten hourglass-shaped PLANTs, for a total of 120. But on February 1st, CE 70, the spacefleet of the Earth Alliance fireda nuclear warhead at the Junius Seven PLANT, destroying it and killing 243,721 innocent civilians, in what later became known as the Bloody Valentine Incident. From that point, and until CE 74 there are PLANTs located at L5. As of late Cosmic Era 73, there is at least one PLANT located at L4]], Armory One, a ZAFT military base. 

In CE 74 Lord Djibril attacks PLANT with the superweapon Requiem in an attempt to destroy Aprilius One. However because of the intervention of the Joule Squad the beam misses its target and instead directly hit Januarius 1-4 and caused December 7 and 8 to collapse, leading to the death of hundreds of thousands of Coordinators.

(http://www.gundamofficial.com/worlds/ce/background/glossary_misc.html#plant)