=1.= _P. ussuriensis_ Maximowicz _Bull. Acad. Sci. St. Petersb._ =15=:132. 1857. =2.= _P. sinensis_ Decaisne _Bull. Acad. Sci. St. Petersb._ =19=:172. 1883. =3.= _P. simonii_ Carrière _Rev. Hort._ 28. 1872. fig. 3. =4.= _P. sinensis ussuriensis_ Makino _Tokyo Bot. Mag._ =22=:69. 1908. Rehder says of _P. ussuriensis_,[15] "This species differs from the allied species chiefly in the short stalk of the globose fruit with persistent calyx, in the broad, often nearly orbicular, strongly setosely serrate leaves and in the lighter yellowish-brown branches; the flower clusters are, owing to the short stalks, rather dense and hemispherical, the petals are obovate and rather gradually narrowed toward the base; the styles are distinctly pilose near the base." Wilson,[16] describing the vegetation of Korea, says of this species: "_Pyrus ussuriensis_ is abundant and this year is laden with fruit. On some trees the fruit is wholly green, on others reddish on one side; the length of the peduncle varies and the same is true of the leaf-structure; the calyx is persistent or deciduous often on fruits on the same branch." The habitat of this species is northern and northeastern China and eastern Siberia. Manchuria, Korea, Amurland, and Ussurri are named as regions in which it is most commonly found. A glance at the map shows that this habitat is in the far north for pears, and it might well be suspected that this would be one of the hardiest of all pears, and this proves to be the case. Horticultural varieties are reported by Chinese explorers, some of which have been introduced by the United States Department of Agriculture. These no doubt have some value in the most northern fruit regions of America and if not for their fruits, they may prove useful in hybridization. But it is as a possible stock resistant to blight that the species has received most attention in this country.