This plum, parentage unknown, was received from Burbank by the New York Experiment Station in 1893 for testing, under the name Japanese Seedling X. While in no way wonderfully remarkable, its earliness, attractive color, good quality and productiveness have been such that it has been retained, the cumbersome name having been changed to Japex. The majority of the characters of the variety are plainly those of Triflora, yet the fruits in appearance would lead one to call it a Domestica. Tree very large, vigorous, vasiform, very productive; branches slender, sparingly thorny; leaf-scars thick; leaf-buds unusually short; leaves obovate or ovate, two and one-quarter inches wide, four inches long; margin finely serrate varying to crenate, with few dark glands; blooming season short; flowers appearing before the leaves; borne in clusters on lateral buds and spurs, singly or in pairs. Fruit very early, season short; one and one-eighth inches in diameter, roundish, dark purplish-red or purplish-black, covered with medium thick bloom; flesh light yellow, very juicy, somewhat melting, sweet next to the skin, but tart near the pit, aromatic; good; stone clinging, three-quarters inch by one-half inch in size, oval. JEFFERSON [Illustration: JEFFERSON] _Prunus domestica_ =1.= Downing _Fr. Trees Am._ 279, 280 fig. 108. 1845, =2.= _Horticulturist_ =1=:11, 93. 1846. =3.= Floy-Lindley _Guide Orch. Gard._ 420. 1846. =4.= Thomas _Am. Fruit Cult._ 325, 326, fig. 251. 1849. =5.= _Mag. Hort._ =16=:453 fig. 25. 1850. =6.= Hovey _Fr. Am._ =2=:1, Pl. 1851. =7.= _Am. Pom. Soc. Cat._ 54. 1852. =8.= Elliott _Fr. Book_ 411. 1854. =9.= Thompson _Gard. Ass’t_ 518, Pl. 1. 1859. =10.= Mas _Le Verger_ =6=:17, Pl. 9. 1866-73. =11.= _Pom. France_ =7=: No. 28. 1871. =12.= Hogg _Fruit Man._ 707. 1884. =13.= Gaucher _Pom. Prak. Obst._ No. 95, Col. Pl. 1894. =14.= _Cornell Sta. Bul._ =131=:188. 1897. _Bingham_ incor. 2, 8. Prune Jefferson 11.