Lobelia longicaulis Brandegee in Univ. Calif. Publ. Bot. 6(4): 73. 1914 sec. Rzedowski 2019
- =Lobelia neglecta Vatke in Linnaea 38: 720. 1874, nom. illeg. syn. sec. Rzedowski 2019
- =Dortmannia neglecta (Vatke) Kuntze, Revis. Gen. Pl. 2: 973. 1891 syn. sec. The Plant List 2013
- =Lobelia plebeia E. Wimm. in Repert. Spec. Nov. Regni Veg. 22: 194. 1926 syn. sec. The Plant List 2013
- =Lobelia urticifolia E. Wimm. in Repert. Spec. Nov. Regni Veg. 22: 195. 1926 syn. sec. Rzedowski 2019
- =Lobelia poasensis E. Wimm. in Ann. Naturhist. Mus. Wien 46: 239. 1932 syn. sec. The Plant List 2013
- =Lobelia longicaulis var. plebeia (E. Wimm.) E. Wimm., Pflanzenr. IV. 276b(2): 507. 1953 syn. sec. The Plant List 2013