[f. SUN sb. + DROP sb.] Any of the species of Œnothera (evening primrose) which open in sunlight.
1796. Nemnich, Polygl.-Lex., Sun drop, Oenothera.
1845–50. Mrs. Lincoln, Lect. Bot., App. 132. Œnothera … fruticosa (shrubby œnothera, sun-drop).
1856. A. Gray, Man. Bot. (1860), 131. Sundrops.
