| Name | Youngia japonica subsp. longiflora Babcock & Stebbins |
| Authorship | Babcock & Stebbins |
| Rank | Subspecies |
| Placed in | Youngia japonica (Linnaeus) de Candolle |
| Citation | 1937 Publ. Carnegie Inst. Wash. 484: 97. |
| Holdings | 11 Specimens held in the Harvard University Herbaria identified as Youngia japonica subsp. longiflora Babcock & Stebbins |
| Identification made in | 2010 (2), 2011 (9) |