| Canada | | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| Canada | | | Anonymous | 1986 | (none) | List-Based Rec., Soil Conserv. Serv., U.S.D.A. | |
| Canada | | | Gleason, H. A. | 1968 | The Sympetalous Dicotyledoneae | Ill. Fl. N.E. U.S. | vol. 3. 596 pp |
| Canada | Newfoundland | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| Canada | Newfoundland | | Gleason, H. A. | 1968 | The Sympetalous Dicotyledoneae | Ill. Fl. N.E. U.S. | vol. 3. 596 pp |
| Canada | Nova Scotia | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| Canada | Ontario | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| Canada | Quebec | | Gleason, H. A. | 1968 | The Sympetalous Dicotyledoneae | Ill. Fl. N.E. U.S. | vol. 3. 596 pp |
| Chile | | | Marticorena, C. F. S. & M. Quezada | 1985 | Catálogo de la Flora Vascular de Chile | Gayana, Bot. | 42: 1–157 |
| China | Liaoning | | Flora of China Editorial Committee | 1998 | Flora of China (Scrophulariaceae through Gesneriaceae) | Fl. China | 18: 1–449 |
| Kazakhstan | | | Flora of China Editorial Committee | 1998 | Flora of China (Scrophulariaceae through Gesneriaceae) | Fl. China | 18: 1–449 |
| Russian Federation | | | Flora of China Editorial Committee | 1998 | Flora of China (Scrophulariaceae through Gesneriaceae) | Fl. China | 18: 1–449 |
| South Africa | | | Gibbs Russell, G. E., W. G. M. Welman, E. Retief, K. L. Immelman, G. Germishuizen, B. J. Pienaar, M. Van Wyk & A. Nicholas | 1987 | List of species of southern African plants | Mem. Bot. Surv. South Africa | 2(1–2): 1–152(pt. 1), 1–270(pt. 2) |
| United States | | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| United States | | | Gleason, H. A. | 1968 | The Sympetalous Dicotyledoneae | Ill. Fl. N.E. U.S. | vol. 3. 596 pp |
| United States | | | Radford, A. E., H. E. Ahles & C. R. Bell | 1968 | (none) | Man. Vasc. Fl. Carolinas | i–lxi, 1–1183 |
| United States | | | Anonymous | 1986 | (none) | List-Based Rec., Soil Conserv. Serv., U.S.D.A. | |
| United States | | | Munz, P. A. | 1968 | (none) | Suppl. Calif. Fl. | 1–224 |
| United States | California | | Munz, P. A. | 1968 | (none) | Suppl. Calif. Fl. | 1–224 |
| United States | California | | Anonymous | 1986 | (none) | List-Based Rec., Soil Conserv. Serv., U.S.D.A. | |
| United States | Illinois | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| United States | Maryland | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| United States | Michigan | | Gleason, H. A. | 1968 | The Sympetalous Dicotyledoneae | Ill. Fl. N.E. U.S. | vol. 3. 596 pp |
| United States | Michigan | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| United States | North Carolina | | Radford, A. E., H. E. Ahles & C. R. Bell | 1968 | (none) | Man. Vasc. Fl. Carolinas | i–lxi, 1–1183 |
| United States | Ohio | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| United States | Washington | | Fernald, M. | 1950 | (none) | Manual (ed. 8) | i–lxiv, 1–1632 |
| United States | West Virginia | | Gleason, H. A. | 1968 | The Sympetalous Dicotyledoneae | Ill. Fl. N.E. U.S. | vol. 3. 596 pp |