Solidago pacifica Juz. is native to the Far East Russia, Sakhalin Is., northeastern China, N. Korea, and a few locations in northwestern Hokkaido Is., Japan (Juzepczuk 1959). It appears to be a robust relative of S. decurrens; both have small heads compared to S. dahurica. I have only seen limited material of this species. Solidago pacifica was not strongly supported in the multivariate analyses of S. ser. Solidago by Semple et al. (2020) with low levels of a posteriori assignment to S. pacifica.
Synonyms: Solidago virgaurea L. var. coreana Nakai, S. decurrens var. coreana (Nakai) Kitamura, and S. virga-aurea var. gigantea Nakai.
No chromosome numbers have been reported under the name S. pacifica.
Futher work is needed to expand sample sizes of S. pacifica in both molecular and morphological studies to determine how best to delimit the species. At this point it appears to be a mixture of atypical specimens of S. decurrens, S. dahurica, and a species intermediate between those two taxa in both morphology and geography.