Plants are inter-dimensional beings that are tapped as a source of power and energy for the planet Gunsmoke. They are beings that can generate energy and even food and water based on environmental conditions. Plants were invented by humans, and are usually kept alive in light bulb shaped containers and used as a power source. Vash and Knives are independent Plants, meaning they can survive outside of a special container normal Plants require to survive. Vash and Knives are two of few sentient Plants, possessing free will and the ability to use their Plant powers whenever they wish (although Vash rarely ever does).
As humanoid plants, the characters Vash and Knives display a few distinct characteristics which separate them from the human race. Most Plants (as shown in their containers) are feminine; however, Vash and Knives are male.
The character Vash shows an extended lifespan beyond the reach of ordinary humans. In the Anime series the character is 130 years old. In the manga version he is aged even more so at 150 years. It is also notable that at the beginning of their lifespan they age very quickly, growing close to the size of an adolescent in a single year, and once they age to adulthood, they seem to not age at all.
Superhuman Abilities Edit
Vash demonstrates superhuman abilities, among them being greater strength, agility and focus which explains his superb marksmanship. Vash also has a higher IQ than most human beings, as mentioned in Rem Saverem, as well as the ability to communicate telepathically.
Both Vash and Knives exhibit the ability to generate incredibly powerful weapons from their bodies. Vash's ultimate weapon, the Angel Arm, is the result of this ability, capable of annihilating entire cities. Knives manifests this same ability.
With an advanced level of control over their Plant ability the user gains the ability to merge and manipulate plant energies. This power is seen in Knives' use of plant matter to increase his own powers throughout the manga. At one point he even attempts to absorb his brother but is overwhelmed at the potent energy source and fails in his goal. Later in the series Knives absorbed enough plants to create an "Ark"- -a floating ship which aided in his attempts to capture the remaining plant life on Planet Gunsmoke. According to the independent Chronica, who came with the rescuing Earth fleet, modern independents are equipped with a mental block that prevents merging. However, the original generation of Plants on Gunsmoke don't have this, and it is this fact coupled with their natural shared conciousness and lack of self-identity that made it so easy for Knives to create the Ark.