Centaris Seven

Centaris Seven, or Centarix VII, is a planet whose plants secrete a corrosive deadly to mechanical beings.

The Dark Heart of Sandokan
Brushguard discovered the corrosive from Centaris Seven and weaponized it into a corrosive gas. He used this gas on the destructive entity Synthos.

The AllSpark Almanac
Centarix VII was part of the Nebulon Republic.