Acronym HH *in the context of TL-2* means "combined libraries \[and collections\] of the Harvard University Herbaria ([[Collection A|A]] and [[Collection GH|GH]])", Cambridge, U.S.A. Currently Harvard University Herbaria ([[Collection A|A]], [[Collection AMES|AMES]], [[Collection ECON|ECON]], [[Collection FH|FH]], [[Collection GH|GH]]) are administered as a single unit, but materials from them should be cited separately. **NB**: Index Herbariorum currently uses acronym HH for Instituto de Investigaciones de la Amazonia Peruana. More information: - List of Harvard University Herbaria at [Index Fungorum](https://sweetgum.nybg.org/science/ih/herbarium-list/?NamOrganisation=Harvard%20University) - List of Harvard University Herbaria at [their own website](https://huh.harvard.edu/pages/herbaria)