with …
leaf shape=symmetric[?]  or
leaf shape=asymmetric[?] :

leaf shape=symmetric

blunt tip (as if cut off)
🇪🇺◼︎ European black alder  Alnus glutinosa

bark=white w/dark blotches; leaf shape=⛛ triangular with long tapered tip
◼︎ gray birch  Betula populifolia

bark=white over orange;  leaf shape= oval;  buds shiny and not sticky
◼︎ American white birch  Betula papyrifera

bark=white;                      leaf shape= oval;  buds sticky with resin
🇪🇺◼︎ European white birch  Betula pendula

teeth or notches=round;  leaf edge=flat
◼︎ white alder  Alnus rhombifolia

teeth or notches=round;  leaf edge=rolled under
◼︎ red alder  Alnus rubra

tree has thorns
◼︎ black hawthorn  Crataegus douglasii

outmost leaves undersurface=glossy and sticky
Sitka alder  Alnus viridis subsp. sinuata

outmost leaves undersurface=dull and not sticky
speckled alder / 🗻︎ mountain alder  Alnus incana

bark=gray or dark-blue;  leaf veins=branched,     base= heart-shaped
American hophornbeam / ironwood  Ostrya virginiana

bark=gray or dark-blue;  leaf veins=unbranched, base= rounded (U-shaped)
American hornbeam / musclewood  Carpinus caroliniana

bark=yellow to red-brown, ragged, shaggy;  leaf base= angular (V-shaped)
♒︎ river birch  Betula nigra

bark=bronze or silver, peeling in thin curly flakes; leaf base=​slightly--heart-shaped
◼︎ yellow birch  Betula alleghaniensis

bark=dark-brown not-peeling;                               leaf base=​slightly--heart-shaped
cherry birch  Betula lenta

usually has multiple trunks;  some leaves symmetric, some not;  some leaves have pointed tips, some rounded;  edible nuts summer-Autumn
American hazelnut  Corylus americana

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plant terminology