Salix sepulcralis group inheritied from its parent the twisted and contorted branches, as well as being more cold-tolerant, as "S. babylonica" var." matsudana" is native to northern China and Korea. These trees are usually no more than tall. Leaves are finely serrulate, pubescent or silky when young. Ovaries are short and flask-shaped, not much longer than the subtending catkin scale. They are usually intermediate between the parent species, showing the typical weeping willow appearance with leaves that are pale glaucous below. But as an ornamental tree with high diversity, trees may look closer to either parent or different entirely. Salix sepulcralis group The
Spathius agrili only attracted to select species of "Fraxinus" and to "Salix babylonica". In natural settings, "S. agrili" will be unlikely to encounter and parasitize non-target larvae as it does not search other tree species. This, in addition to other tests of host specificity, led to approval of the wasp for controlled releases in specific study sites in the United States for further research. Spathius agrili Spathius agrili is a parasitic non-stinging wasp of family Braconidae which is native to North Asia. It is a parasitoid of the emerald ash borer ("Agrilus planipennis" Fairmaire), an invasive species which has destroyed tens of