It has been very difficult to establish a satisfactory nomenclature for the Triflora plums now grown in America. In spite of the excellent work of Berckmans,[105] Bailey[106] and Waugh,[107] in bringing order out of what was at one time utter confusion, there is still a great deal of uncertainty as to the identification of some varieties. The confusion began with the first extensive importation of these plums from Japan when names which the Japanese applied to classes or groups or the localities from which the plums came were made to apply in America to definite varieties. Many of the names under which the plums were imported have had to be dropped and the varieties boldly renamed. Another source of confusion has been that these, of all plums, seem most variable under changed conditions. Local environment in many instances in America changes somewhat the habit and appearance of varieties, making it difficult to decide whether two or more specimens of the same sort from different localities are identical varieties or distinct. Curiously enough, too, the trees of some varieties of plums seem to bear unlike fruit in different years, especially in the matter of time of ripening; that is, trees of some varieties do not always ripen their fruit in the same sequence, being earlier than another variety one year and possibly later the next. All fruits are more or less variable in this respect, but the Triflora plums are remarkably so, a fact that has added to the confusion in their nomenclature, since it adds to the difficulty of identifying varieties. The cultivated varieties of _Prunus triflora_ are also very diverse as regards tree-characters, especially as to vigor, hardiness and time of maturity of the fruit. The differences seem to be horticultural or those that come from cultivation, rather than botanical. Indeed, it seems impossible to place the numerous varieties in horticultural groups that are marked with any great degree of definiteness. A distinction of groups based on color is sometimes made, but the one character is insufficient to have classificatory value. In Japan, according to Georgeson, a division of the species is made with shape as the line of division. He says[108] “The round plums are designated by the term botankio, while those of an oval or pointed shape are called hattankio.” The varieties are sometimes loosely grouped into yellow and red-fleshed sorts. A serviceable classification would have to be founded on several or a considerable number of characters. Such a classification at present is impossible. =9.= =PRUNUS SIMONII= Carrière =1.= Carrière _Rev. Hort._ 111. 1872.[109] Tree small, of medium vigor, upright, dense, hardy except in exposed locations, unproductive; branches stocky, long, rough, thickly strewn with small lenticels; branchlets slender, long, with internodes of medium length, reddish, glabrous; leaf-buds intermediate in size, short, obtuse, free.