The first time I heard reference to the term was when Michael Pawlyn in a video inerview at the 'Radical Nature' exhibition compared it to Biomimicry. Biomorphism more simply than biomimicry imitates the forms of nature without quite understanding the forms in the way that biomimicry might.
In researching the term "biomorphic", I have found more reference to early 20th century art, than I have of architecture bar some references to zoomorphic and anthropomorphic architecture. The more common link I found between biomorphism and architecture was organic architecture whose ideas refer not only to the buildings' literal relationship to the natural surroundings, but how the buildings' design is carefully thought about as if it were a unified organism.
With my understanding of ecosystems, biomimicry and biomimetics, I see biomorphism as an early conceptual idea that paved the way for biomimicry and biomimetics to enter the scene. Biomorphism still has an important role to play in regard to understanding the ordering systems that nature employs. It is a term that can be attributed to architecture theory as shallow as the Crocodile Hotel in Darwin or as deep as the thought patterns behind Jorn Utzon during the design of the Sydney Opera House.