Stem and twigs=not noticeably hairy from several steps back;  no milky juice from leaf injury;  can be full tree height

leaves=small (<18 cm) (<7 in), leaflets=small   (<4 cm)  (<1½ in) or
leaves=large (>20 cm) (>8 in), leaflets=large (4-20 cm) (1½-8 in);  nuts on or under tree   >   hickory/pecan/walnut family Juglandaceae :

Leaves=small (<18 cm) (<7 in), leaflets=small (<4 cm) (<1½ in)

leaflet teeth each tipped by stiff sharp spine;  evergreen;  🍒︎ ripe fruits dark blue   >   Oregon grape Mahonia aquifolium

leaflet tips=∧ pointed, undersurface=hairless   >   🗻︎ American mountain ash Sorbus americana
leaflet tips=∩ blunt,     undersurface=hairy       >   🗻︎ European mountain ash Sorbus aucuparia

Crushed leaves=aromatic;  nut husks do not separate into sections

end leaflet usually missing:  even-pinnate;  middle of leaflet curved a bit more than butternut   >   eastern black walnut Juglans nigra
end leaflet usually exists:     odd-pinnate;  middle of leaflet curved a bit less than eastern black walnut   >   butternut Juglans cinerea

Learn more

plant terminology