The term "long-branched" refers to something that has many branches extending from a central point, often creating a tangled or complex structure. Some synonyms for "long-branched" could include "multi-branched," "ramified," or "heterogeneous." Other options might include "interconnected," "networked," or "entangled." These terms all convey a sense of complexity and branching that is characteristic of the long-branched structure. Whether you are describing the branches of a tree, the structure of a river network, or the complex relationships within a social system, using these synonyms can help you to convey a clear and descriptive image to your readers.