Tellusian is a gender element from the element system. It is associated with the element of earth and a "neutral" gender element. The neutral element is not masculine, feminine, or xenine but still present. It can be described as being similar to neutrois or maverique. Earth is used to represent it because it has been frequently used to represent neutral concepts, identities, and terms. One whose gender element is purely neutral would be called tellusian. The noun form of the word is tellusi (ex: I am tellusi). The term can be combined with other gender terms, such as demitellusian, or tellusiboy.
The term tellusian and the flag were made on the Tumblr blog Genderelementarchive on December 23, 2017.
The flag's colors are brown and green, representing the element of earth. In the center it has an upside down triangle with a line through it- the alchemical symbol for earth.
Tellusian comes from the Latin word tellus, meaning "earth".