| Name | Heterothecium grossum (Persoon ex Nylander) Tuckerman |
| Authorship | (Persoon ex Nylander) Tuckerman |
| Rank | Species |
| Placed in | Heterothecium Flotow |
| Citation | 1888 Syn. N. Amer. Lich. 2: 54 |
| Holdings | 2 Specimens held in the Harvard University Herbaria identified as Heterothecium grossum (Persoon ex Nylander) Tuckerman |
| Identification made in | [no date] (2) |