Identify trees online for free

Glossary

Diagram of select glossary terms.

ALTERNATE
leaves that are staggered or not placed directly across from each other on the twig.
BLADE
the flat part of a leaf, or leaflet, characteristic of broadleaf trees.
BRACT
a modified leaf that bears a flower.
BROADLEAF
a tree with leaves that are flat and thin and generally shed annually.
BUD SCAR
the marks remaining after bud scales drop in spring.
COMPOUND LEAF
a leaf with more than one blade. All blades are attached to a single leafstem. Where the leafstem attaches to the twig there is a bud.
CONIFER
cone-bearing tree.
DECIDUOUS
shedding all leaves annually.
ENTIRE
a leaf margin with smooth, untoothed edges.
EVERGREEN
trees with needles or leaves that remain alive and on the tree through the winter and into the next growing season.
INVASIVE
plant known to reproduce rapidly and quickly spread over a large area.
LEAF SCAR
the mark left on the twig where the leaf was previously attached.
LOBES
projections that shape a leaf.
MARGIN
the edge of a leaf.
MIDRIB
the primary rib or central vein of a leaf.
OPPOSITE
2 or 3 leaves that are directly across from each other on the same twig.
PALMATE
blades or lobes or veins of the leaf arranged like fingers on the palm of a hand.
PERSISTENT
remains on the tree for more than one year.
PETIOLE
the leafstalk that connects the blade(s) to the twig.
PINNATE
blades or lobes or veins of the leaf arranged like the vanes of a feather.
SAMARA
winged fruit.
SIMPLE LEAF
a single leaf blade with a bud at the base of the leafstem.
SINUS
indentation between lobes on a leaf.
SPURS
stubby, often sharp twigs.
TEETH
notches on the outer edge of a leaf.

© 2008 Arbor Day Foundation