| FERN [20] | |
| V.L. Komarov (Komorov), Fl. URSS, vol. 1 : p. 81, t. 3, fig. 1-10 (1934-1964) [22] | |
| Illustration contributed by: | Smithsonian Institute, Washington, D.C., U.S.A. |
V.L. Komarov (Komorov), Fl. URSS, vol. 1 : p. 81, t. 3, fig. 1-10 (1934-1964)