Waugh[119] has given the name _Prunus hortulana robusta_ to a group of hybrid plums of which _Prunus triflora_ and various native varieties are the parents. For most part these hybrids resemble the American more than the Asiatic parent. Since these plums differ so among themselves it is doubtful if more can be said as to the characters of Waugh’s group than to mention the above resemblance. Some thirty or more varieties fall into this group of which America, Golden, Juicy, Ruby, Waugh and Gonzales are chief. =PRUNUS HORTULANA MINERI= Bailey [Illustration: _PRUNUS HORTULANA MINERI_] =1.= Bailey _Cornell Sta. Bul._ =38=:23, 1892. =2.= Waugh _Vt. Sta. An. Rpt._ =10=:103. 1897. =3.= Britton and Brown =2=:247, 1897. It is impossible from present knowledge to say certainly whether the Miner-like plums put by Bailey into a botanical sub-division of _Prunus hortulana_ are extreme variations of the species or, as Bailey in his last accounts and Waugh at all times have supposed, are hybrids between _Prunus hortulana_ and _Prunus americana_. It is certain that all of these plums are intermediate in some characters between the two species named; neither botanists nor pomologists can agree as to whether certain varieties belong to the one or the other botanical division. There are, however, in several herbaria, specimens from the wild, and from different localities, that indicate that there is a distinct plum toward the northern limit of the range of _Prunus hortulana_ which, if a natural hybrid, is of so ancient hybridity that the plants now come measurably true to type. The chief representatives of the Miner-like plums under cultivation, as Miner, Forest Rose, Prairie Flower and Clinton, are so like these wild plums as to lead the writer to believe that Bailey’s botanical sub-division is justified and is worth continuing even though a considerable number of the varieties now put with Miner, most of which have originated under cultivation, are hybrids and that the wild plums may have come from natural hybrids of more or less remote time. The sub-species differs from the species in having shorter, stiffer, less graceful branches; leaves smaller, thicker, rougher and of a bluish-green cast; the blossoms of the two are much the same but those of the sub-species open a few days earlier; the fruits of the sub-species are larger than those of the species, lighter red, have more bloom, are less firm in texture, ripen earlier, yet later than those of any other species, and are quite different in flavor, having more nearly the taste of the fruit of _Prunus americana_; the stones, as well as the fruits, are very different, being in the sub-species larger, broader, flatter, smoother and less pointed. The differences in fruit and stone, and to some extent in the leaves, can be seen if the color-plates of Forest Rose and Wayland be compared.