with …

thorns = pointed twigs and leaf=🍂︎ non-lobed, and …
tip=long tapering, undersurface=vein network intricate
American plum  Prunus americana

undersurface=wooly hair
🍎︎ common apple  Malus pumila

undersurface= smooth
🍐︎ common pear  Pyrus communis

-OR-

thorns = pointed twigs and leaf=somewhat-♧-lobed, and …
twigs, petioles, leaf undersurface=​woolly
🍎︎ prairie crabapple  Malus ioensis

twigs, leaves=not woolly
🍎︎ wild crabapple  Malus coronaria

Learn more

plant terminology