The alkaloids of Fumaria parviflora Lam. (F. caespitosa Loscos) (Papaveraceae) (1) have been the subject of several investigations (2–26). From these studies, the following alkaloids have been identified: adlumiceine (2, 3), adlumidiceine (2, 4), (+)-adlumidine (5), (+)-adlumine (5), (—)-adlumine (6), (+)-bicuculline (5–8), (±)-bicuculline (3, 11), bicucullinine (narceimine) (11), (—)-cheilanthifoline (3, 5), coclaurine (3), coptisine (7), (—)-corlumine (5), cryptopine (3, 6, 8), dehydrocheilanthifoline (12), dihy drofumariline (4), dihydrosanguinarine (3), fumaramidine (7), fumaramine (6, 7, 14–16), fumaridine (6, 7, 14–16), fumariflorine ethyl ester (7), fumarilicine (10), (+)-fumariline (7), fumaritine (7, 10), (+)-α-hydrastine (6, 7), (+)-isoboldine (3, 7), izimirine (17), lahoramine (18), lahorine (18), 8-methoxydihy drosanguinarine (13), methylhydrastiniuni (19), N-methyladlumine (3), N-methyihydrasteine (9, 19), N-methylhydrastine (9), N-methyloxohydrasteine (9, 19), narlumidine (20), norjuziphine (3), noroxyhydrastinine (7), 8-oxocoptisine (4), oxysanguinarine (3, 4), (+)-parfumidine (7, 8, 10), (+)-parfumine (7, 10, 21), (+)-parviflorine (7, 10), protopine (3, 6, 7, 8, 22, 23), the quaternary salt of protopine (24), sanguinarine (3, 25), (— bscoulerine (3), (—)-stylopine (7), and (±)-stylopine (26). We now describe the isolation and identification of rhoeagenine from the leaves and twigs of this species. This is the first rhoeadine-type alkaloid from Fumaria. The rhoeadine alkaloids are biogenetic derivatives of protopines, and direct evidence exists for the incorporation of labeled protopine into rhoeadine in Papaver rhoeas L. (27). Rhoeadines have only been found among the Papaveraceae where they are concentrated in the closely related genera Papaver and Meconopsis, with an isolated occurrence in Bocconia (28, 29). All the sections of Papaver contain rhoeadines, but the abundance and distribution of the different alkaloids varied considerably from one section to another. The sources of rhoeagenine are described in a recent review on rhoeadine alkaloids (30). © 1985, American Chemical Society. All rights reserved.