Charlotte Lindqvist and Victor A. Albert (2002), "Origin of the Hawaiian endemic mints within North American Stachys (Lamiaceae). Figure 1", American Journal of Botany, 89 (10): 1709–1724, doi:10.3732/ajb.89.10.1709, PMID21665597
nih.gov
pubmed.ncbi.nlm.nih.gov
Charlotte Lindqvist and Victor A. Albert (2002), "Origin of the Hawaiian endemic mints within North American Stachys (Lamiaceae). Figure 1", American Journal of Botany, 89 (10): 1709–1724, doi:10.3732/ajb.89.10.1709, PMID21665597