where basal 2 side veins are slightly more conspicuous than others, and …
leaf juice=milky
mulberry  genus Morus

leaf=asymmetric, narrow;  bark=very thick vertical ribs, looks covered with warts or puffy paint
hackberry  Celtis occidentalis

leaf=asymmetric, broad, hairless
American basswood  Tilia americana

leaf=asymmetric, broad, undersurface=​white + velvety
white basswood  Tilia heterophylla

OR it does NOT (meaning the side veins are about equal size), and …

leaves=very narrow, twigs=slender+limber, buds covered by one scale, and …
leaf hairy white silky
white willow  Salix alba

leaves and twigs droop
weeping willow  Salix babylonica

leaf= rounded
black willow  Salix nigra

uppersurface=pale green, undersurface=​paler
peach-leaved willow  Salix amygdaloides

Learn more

plant terminology