From "The Notebooks of A. P. Saunders", Book 3, p. 61:
"Macrophylla x Mlokosewitschi
5397-8 2785 (Mloko) X Macro
5397 1932 May 23. Among the earliest. After macro & before mloko. Flowers pale yellow like wittmanniana. Foliage very coarse, very light green..."
[From
American Peony Society Bulletin, December 1945:] "No. 5397 is a cross between Mlokosewitschi and macrophylla (tomentosa). The flowers are pale yellow, the foliage very coarse, very light green. The odor of the leaves is faint and suggests cloves. The pollen is extraordinarily fertile and there is no difficulty in crossing this plant with an Officinalis variety like Otto Froebel."