| Name | Isopterygium planissimum var. laxirete Thériot |
| Authorship | Thériot |
| Rank | Variety |
| NomenclaturalStatus | NomLeg |
| Placed in | Isopterygium planissimum Mitten |
| Citation | 1931 Smithsonian Misc. Collect. 85(4): 43 |
| Holdings | 2 Specimens held in the Harvard University Herbaria identified as Isopterygium planissimum var. laxirete Thériot |
| Identification made in | [no date] (1), 2019 (1) |