=1.= Quintinye _Com. Gard._ 67, 69. 1699. =2.= Langley _Pomona_ 95, Pl. XXV fig. III. 1729. =3.= Duhamel _Trait. Arb. Fr._ 105, Pl. XVIII. 1768. =4.= Kraft _Pom. Aust._ =2=:45, Tab. 200 fig. 2. 1796. =5.= Miller _Gard. Dict._ 3. 1807. =6.= Forsyth _Treat. Fr. Trees_ 20. 1803. =7.= _Pom. Mag._ =1=:33. 1828. =8.= _Lond. Hort. Soc. Cat._ 148. 1831. =9.= Prince _Pom. Man._ =2=:60. 1832. =10.= Downing _Fr. Trees Am._ 290. 1845. =11.= Floy-Lindley _Guide Orch. Gard._ 287, 383. 1846. =12.= Thomas _Am. Fruit Cult._ 344. 1849. =13.= Elliott _Fr. Book_ 416. 1854. =14.= McIntosh _Bk. Gard._ =2=:529. 1855. =15.= Thompson _Gard. Ass’t_ 515. 1859. =16.= Mas _Pom. Gen._ =2=:101. 1873. =17.= _Am. Pom. Soc. Cat._ 36. 1877. =18.= Hogg _Fruit Man._ 687. 1884. =19.= Mathieu _Nom. Pom._ 423, 452. 1889. =20.= _Guide Prat._ 161, 358. 1895. Blue Perdrigon, of some 2. Blaue Kaiserin 19. Blue Imperatrice 9, 10, 12, 13, 14, 15, 17, 18. _Blue Imperatrice_ 16, 19. Die Veischenfarbige Kaiserinnpflaume 4. Empress I. _Empress_ 5, 6, 9, 18, 19. _Fürsten Zwetsche_ 19. _Fürstenzwetsche_ 20. _Hoheitspflaume_ 19, 20. Imperatrice Blue 8. _Imperatrice_ 7, 8, 9, 10, 12, 13, 14, 15, 18, 19. Imperatrice Violette 3, 16, 20. _Imperatrice Violette_ 4, 7, 8, 9, 10, 11, 13, 14, 15, 18, 19. _Late Red Imperial_ 9. _Late Violet_, of some 2. _Prinzessin Pflaume_ 19. Prune d’Altesse? 9. _Red Magnum Bonum_ 9. _Red Imperial_ 9. Smith’s large October? 9. The Imperatrice Plum 7. _Veritable Imperatrice_ 8, 10, 13, 14, 15, 19. _Violette_ 8, 10, 13, 14, 15, 19. Violette Kaiserin 19. _Violette Kaiserin_ 16, 20, _Violet Empress_ 9, 19. Imperatrice has been long known and widely grown but the variety has no especial cultural value in the United States, the fruit being too small and too poor in quality. If it has any merit, it is keeping quality, the fruit hanging well on the tree and keeping well, even improving after picking. This is an old variety, well known in Austria, France and England during the Seventeenth and Eighteenth Centuries. Like most long-known varieties its nomenclature is badly confused. Writers have confounded it with Semiana, the Perdrigons, German Prune and other plums of similar appearance. Duhamel regarded this variety as Perdrigon Late, holding that the true Imperatrice is nearly round. Calvel, also, describes a roundish plum under this name in his _Traite Complet sur les Pepinieres_. It is probable, however, that both Duhamel and Calvel were mistaken as all other authors describe an obovate plum. This variety was introduced into America early in the last century but has never become popular. It is of interest, nevertheless, since it has been a leading European variety, is a parent of a number of other varieties and its name is given to a group of plums. The American Pomological Society added it to its fruit catalog list in 1877, but dropped it in 1883.