Specific perennial plant species, such as Arabidopsis halleri and Populus trichocarpa, are explicitly recognized and utilized as standard biological models in scientific research.
The claim states that specific perennial plant species serve as standard biological models in research. Retrieved papers 0 and 7 explicitly identify perennial species (Arabidopsis halleri and Populus trichocarpa) functioning as established biological models in ecological genomics and woody transgenic research respectively, directly supporting the claim.