In Daoism the Earth is the Mother aka Mother Earth as alchemical secret of Green Dragon (eight Trigrams of Bagua)

 People have been reading my blogpost "why the dragon is female" that I uploaded as an academia article. People don't read blogs but they do read academia articles! This inspires me to reread my research to study it better.  There's a quote near the end of the article that explains that since the metal is hidden in the water therefore the son (water) must become the mother. The Mother is Kun as Earth that creates the embryo. 

So the Metal (mother that is now Earth) because the son... the Yang Shen is thus the HEAVEN created by the yin qi adding to the yang qi (EARTH) hidden in the water alchemically via the "Po soul" of the lungs... and thus the Wuji is the harmony of the hidden yang qi (metal) and yang shen (golden immortal body).

In the Bagua (Eight Trigrams) system, Kun (or K'un) represents Earth. It is the symbol for the receptive force, often associated with the mother, yielding, nurturing

http://www.iching123.com/trigram_a_text.htm 

 

• Kan (坎): Water ☵
• Qian (乾): Heaven ☰
• Kun (坤): Earth ☷ 

• Bagua - Wikipedia

  Bā Guà (八卦) Eight Passages * ☰ Heaven 乾; Qián, warming. * ☳ Thunder 震; Zhèn, storming. * ☵ Water 坎; Kǎn, pooling. * ☶ Mountain 艮; ...

  
  

  
• I Ching Trigram Symbolism: A Practical Guide to Interpreting ...

  Qian (Heaven) ☰

  Kun (Earth) ☷

  Zhen (Thunder) ☳

  Xun (Wind) ☴

  Kan (Water) ☵

  Li (Fire) ☲

  Gen (Mountain) ☶

  Dui (Lake) ☱

  
  
• The Eight Trigrams - The Taoist I Ching

  The trigrams Heaven ☰, Earth ☷, Fire ☲, and Water ☵ have multiple meanings. Understanding them is not simply a matter of gathering...

  

  The Taoist I Ching